Speaker 1: Welcome to text Stuff, a production from my Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I am your host,
Speaker 1: Jonathan Strickland. I'm an executive producer with I Heart Radio
Speaker 1: and I love all things tech. And in a previous
Speaker 1: episode called How Music Works the Physics, I talked a
Speaker 1: lot about the basic underlying science behind music and that
Speaker 1: included how sound works and concepts like overtones, harmonics, resonance,
Speaker 1: and more So. If you haven't heard that episode, I
Speaker 1: really recommend you check it out. It will give you
Speaker 1: the underlying principles on what I'm gonna build on today,
Speaker 1: and it's gonna give a lot more of what I'll
Speaker 1: be saying in this episode more context. However, you're like, yeah, no,
Speaker 1: I'm good, let's do this. I'll just say this. Remember
Speaker 1: that playing any note on most musical instruments produces a
Speaker 1: fundamental frequent See that's the note that we hear that's
Speaker 1: being played, as well as a series of overtone frequencies,
Speaker 1: and it's those overtones that shape the sound and give
Speaker 1: it the quality we associate with that specific instrument. We
Speaker 1: call it timber. And that's why a C note played
Speaker 1: on a flute sounds different than the same C note
Speaker 1: played on a recorder or a guitar or a xylophone.
Speaker 1: If it weren't for these overtones, the notes played on
Speaker 1: instruments would sound more similar to one another. There'd be
Speaker 1: no real point in making different instruments. But as we know,
Speaker 1: musical instruments have their own distinct qualities. Before we move
Speaker 1: on to specific groups of musical instruments, I do want
Speaker 1: to talk a tiny bit about music theory, but only
Speaker 1: a tiny bit, because one, music theory gets really complex
Speaker 1: and very specific and it requires a lot more discussion
Speaker 1: than I can cover in an episode. And two I
Speaker 1: get really lost in the weeds pretty early on with
Speaker 1: music theory. If I'm being on a I am not
Speaker 1: a musician. I've never taken courses in music theory. All
Speaker 1: the learning I've done has been on my own, and
Speaker 1: I am admittedly a novice in the field. But while
Speaker 1: I've talked about frequencies and pitches and stuff, I haven't
Speaker 1: really talked about why we have specific notes in Western music.
Speaker 1: Why do we have the notes we have. The notes
Speaker 1: in Western music are A A sharp, B, C C sharp,
Speaker 1: D D sharp, E, F F sharp, G n G sharp.
Speaker 1: Each of those represents a specific frequency, or rather I
Speaker 1: should say frequency s because you can have different octaves
Speaker 1: of the same note. Right, you can have an A
Speaker 1: and then go up an octave. You still have an A,
Speaker 1: but it's twice the frequency of your previous A. Each
Speaker 1: note in this sequence is a semi tone apart from
Speaker 1: the previous note, as well as a semi tone apart
Speaker 1: from the following note, and collectively it's called the chrome
Speaker 1: matic scale. Now I could have started on any one
Speaker 1: of those notes, and after the letter G you wrap
Speaker 1: back around to the letter A and get back to
Speaker 1: my starting point. That's still a chromatic scale, but it
Speaker 1: raises a question like why is there an A note?
Speaker 1: Why does the sequence go up to G? Why do
Speaker 1: all notes except B and E have sharp notes? What
Speaker 1: even defines a note? These pitches correspond to frequencies that
Speaker 1: Western musicians and audiences have found appealing over time, and
Speaker 1: so it kind of solidified out of what people liked.
Speaker 1: There are other music scales, by the way, such as
Speaker 1: the diatonic scale. While the chromatic scale includes the twelve
Speaker 1: semi tones found in Western music, the diatonic scale is
Speaker 1: a scale of seven notes, five whole tones, and two
Speaker 1: semi tones and do re mi fa, so lat do
Speaker 1: that little bit you've heard if you've ever listen the
Speaker 1: sound of music that represents a diatonic scale. And it
Speaker 1: gets way more complicated than all this. But to really
Speaker 1: dive into that, we'd have to go into a whole
Speaker 1: history of music and the development of music theory and philosophy,
Speaker 1: and we'd have to talk about ratios and major keys
Speaker 1: and minor keys, and honestly, it's way more than what
Speaker 1: we really need to consider for this episode. The important
Speaker 1: thing for us to note, ha ha ha, is that
Speaker 1: the pitches represented in the chromatic scale tend to be
Speaker 1: the ones that Western musical instruments are designed to replicate
Speaker 1: when they are properly tuned. So you can think of
Speaker 1: musical instruments as being a reflection of our natural kind
Speaker 1: of affinity towards these particular notes in the West. And
Speaker 1: I have to keep saying that because music, while it
Speaker 1: is a universal thing among humans that you know, we
Speaker 1: make music, it's not a universal set of laws across
Speaker 1: all cultures. All right, I got all that out the way.
Speaker 1: Let's talk about the general classifications of modern instruments, and
Speaker 1: for the purposes of this podcast. Again, I'm just talking
Speaker 1: about the typical instrument groupings that you would find in
Speaker 1: a Western orchestra. And I realized this brings a lot
Speaker 1: of cultural baggage into the discussion. But just know that
Speaker 1: the examples I give are meant to represent large groups
Speaker 1: of instruments across different cultural boundaries that share, you know,
Speaker 1: similar qualities. If after I cover all the major classifications
Speaker 1: in Western orchestras, I have a bit of extra time,
Speaker 1: we'll tackle some stuff that isn't typically part of those ensembles.
Speaker 1: There's one in particular that I know I'm going to
Speaker 1: cover that you don't typically find in an orchestra. Now,
Speaker 1: out of all the categories of those musical instruments, I
Speaker 1: would say percussion is the easiest to explain. Now, I
Speaker 1: do not mean it's the easiest to play by any means,
Speaker 1: because I think playing any musical instrument requires skill and
Speaker 1: lots of practice and dedication, especially if you want to
Speaker 1: do it well. Also, you've got to remember that my
Speaker 1: original co host and the co creator of tech Stuff,
Speaker 1: Chris Palette, is himself a talented drummer. He played professionally
Speaker 1: and stuff, and while I always like to give him
Speaker 1: a bit of the business when it comes to drumming
Speaker 1: and whether or not it counts as music. In truth,
Speaker 1: I acknowledge that being a great percussionist is really to
Speaker 1: be an accomplished musician. Percussion instruments are, of course the
Speaker 1: kind you strike or rub or otherwise you know, cause
Speaker 1: to vibrate directly, and they're probably the oldest subset of
Speaker 1: musical instruments, as it seems like we'd probably figure out
Speaker 1: pretty early on as human beings that if you hit
Speaker 1: that thing with that other thing, it makes a pretty
Speaker 1: cool sound. But this is all a guest based on intuition.
Speaker 1: We really don't know when humans first started making music,
Speaker 1: except it was definitely before last Wednesday. Percussive instruments produced vibrations,
Speaker 1: as I said, after being struck or rubbed or scraped.
Speaker 1: And there are a couple of instruments that occasionally get
Speaker 1: grouped with percussion, perhaps because it's hard to figure out
Speaker 1: where else to stick them because they aren't your traditional instruments.
Speaker 1: But I'm going to ignore those because they are the outliers.
Speaker 1: So generally you're talking about stuff like drums, xylophones, symbols,
Speaker 1: that kind of thing. There are also instruments that span
Speaker 1: percussion and other categories like stringed instruments, and the most
Speaker 1: obvious example of this type of instrument is the piano
Speaker 1: or the piano forte. Because the piano has strings, obviously,
Speaker 1: but those strings are struck rather than plucked or strummed
Speaker 1: or bode. There are little hammers inside the piano. They
Speaker 1: swing when their respective key is pressed on the keyboard,
Speaker 1: and the hammer strikes its respective string, which then vibrates
Speaker 1: at its fundamental frequency. And that's determined by a lot
Speaker 1: of stuff, including the length of the string, what the
Speaker 1: string is made of, the thickness of the string, and
Speaker 1: how much tension is on it. But a standard piano
Speaker 1: has a D eight keys, some have more, many have fewer,
Speaker 1: but that means they also if they have a D
Speaker 1: eight keys, they have a D eight strings and usually
Speaker 1: eighty eight hammers. Will transition over to stringed instruments in
Speaker 1: a second since we're on the subject, but really, percussion
Speaker 1: is is one of the simplest ones for me to
Speaker 1: explain from a physics perspective. The only other thing I
Speaker 1: might mention is that some percussion instruments are said to
Speaker 1: be pitched, meaning they can produce musical notes of one
Speaker 1: or more pitches, and some are considered unpitched, meaning they
Speaker 1: produce a sound of indefinite pitch. So a xylophone is
Speaker 1: a pitched percussion instrument, as each wooden bar produces a
Speaker 1: different pitch when you strike it with a hammer. Symbols
Speaker 1: or shakers or bass drums and similar instruments are said
Speaker 1: to be unpitched, and this is a good time to
Speaker 1: talk about why some sounds are considered unpitched. Some sounds
Speaker 1: consist of numerous frequencies at similar levels of amplitude, and
Speaker 1: amplitude is volume. You know. Remember in the previous episode
Speaker 1: I was talking about overtones and how most musical instruments
Speaker 1: produce not just a fundamental frequency, but several other frequencies,
Speaker 1: and those other frequencies are typically at much lower amplitudes
Speaker 1: than the fundamental, so we don't hear them as distinct pitches.
Speaker 1: But some instruments produce multiple frequencies of sound at near
Speaker 1: equal amplitudes, and we get this weird combination effect. Audio
Speaker 1: engineers will talk about the color of noise, and you've
Speaker 1: likely encountered examples of this, such as white noise or
Speaker 1: pink noise. White Noise is any collection of equally spaced
Speaker 1: frequencies of sound within a specific bandwidth, all at the
Speaker 1: same amplitude. So the high frequencies and the low frequencies
Speaker 1: all are at the same volume, and you get that
Speaker 1: white noise. This is going to come back to play
Speaker 1: a little bit later. The other colors of noise describe
Speaker 1: distributions of amplitude that either increase or decrease with bands
Speaker 1: of frequencies, so that you get louder high frequencies than
Speaker 1: low frequencies. That's pink noise, or you get the opposite,
Speaker 1: you know, higher low frequencies than than the high frequencies
Speaker 1: that would be blue noise. So unpitched percussion instruments produce
Speaker 1: sounds that are closer to noise. Not that this means
Speaker 1: they are unpleasant, but rather the frequencies of sound they
Speaker 1: produce are such that we do not perceive a specific
Speaker 1: note or pitch with them. Now that we've got the bing,
Speaker 1: bang boom stuff out of the way, let's talk about
Speaker 1: instruments that use either strings or air to create sound.
Speaker 1: And if we peek at the physics behind these instruments,
Speaker 1: we're going to see that they rely on the same
Speaker 1: underlying thing, which are called standing waves. So what is that, Well,
Speaker 1: there are different kinds of waves. You've got traveling waves,
Speaker 1: So these are waves that start at one point and
Speaker 1: then they travel down through whatever medium they're going through.
Speaker 1: If you had a way of seeing the wave, you
Speaker 1: would actually watch as it started at a point of
Speaker 1: origin and move all the way through its medium. You
Speaker 1: could follow it from start to finish. Standing waves are
Speaker 1: a bit different. This is another tough concept to get
Speaker 1: across without visual aids. But imagine you've got a slinky
Speaker 1: and you've attached one into the wall, so you've you
Speaker 1: glued one end of a slinky to wall. Don't actually
Speaker 1: do this, and then you stand far enough back where
Speaker 1: you've stretched the slinky out from the wall to you
Speaker 1: so it's nice and tight, and you send a quick
Speaker 1: pulse by moving the slinky up and then down, and
Speaker 1: you just whip it down the length. You would be
Speaker 1: able to watch that go all the way to the wall.
Speaker 1: It would hit the wall, and then this pulse would
Speaker 1: reflect off the wall. But because that that side of
Speaker 1: the slinky is actually anchored to an unmoving point, uh,
Speaker 1: then that reflection will get inverted. The pulse will be
Speaker 1: as if it were a down then up as opposed
Speaker 1: to an up then down, and it will come back
Speaker 1: the length of the slinky. Now, let's say just as
Speaker 1: the wave is reflecting, you introduce a second pulse down
Speaker 1: the length of the slinky in the original orientation of
Speaker 1: the first pulse, So you're going up and then down. Now,
Speaker 1: that mean that these two pulses, as they're traveling toward
Speaker 1: one another, are inverted with respect to each other, and
Speaker 1: once they pass through the center point, they undergo what's
Speaker 1: called destructive interference. In the very middle of the slinky,
Speaker 1: you would have no movement. It would be equilibrium, and
Speaker 1: the two pulses would pass through and continue on for
Speaker 1: the rest of the length of the slinky, But that
Speaker 1: little middle point, which we would call a node, wouldn't move.
Speaker 1: So the points in a standing wave that maintain equilibrium
Speaker 1: that do not oscillate are the nodes. The oscillating points
Speaker 1: with the greatest amplitude or deviation from the equilibrium are
Speaker 1: called anti noodes. And you can actually see this on
Speaker 1: the string of a guitar. If you were to strum
Speaker 1: a guitar string and slow things down, you'd see all
Speaker 1: the points along the string that are still relative to
Speaker 1: the links on either side. They're going up and down,
Speaker 1: like if you were doing this super slow motion with
Speaker 1: a strobe light effect, you would really be able to
Speaker 1: see it, and it's kind of trippy. And that is
Speaker 1: a standing wave. The wave does not appear to move.
Speaker 1: You see the peaks and troughs going up and down,
Speaker 1: but you have these fixed points, these nodes that are
Speaker 1: not moving, and so the wave doesn't seem to be
Speaker 1: moving down the length of the medium. It just seems
Speaker 1: to be this up and down oscillation on either side
Speaker 1: of these anchored nodes. So that's a standing wave. And
Speaker 1: wind instruments do this just like stringed instruments do, except
Speaker 1: in wind instruments we're talking about the movement of a
Speaker 1: column of air that's the medium, as opposed to a string.
Speaker 1: So instead of a physical string between two anchor points,
Speaker 1: we're talking about a column of air inside an instrument,
Speaker 1: and we're going to get back to that a little
Speaker 1: bit later in this episode. Alright, so let's get to
Speaker 1: those stringed instruments. Producing notes on stringed instruments involves plucking, strumming, bowing,
Speaker 1: or otherwise causing strings to vibrate, which produces the corresponding
Speaker 1: sound of the musical instrument. The sound produced, as I
Speaker 1: mentioned with the piano, depends upon the length of string,
Speaker 1: what the string is made of, how thick or stiff
Speaker 1: the string is, and the amount of tension on that string,
Speaker 1: Plus the overall design of the musical instrument matters as well,
Speaker 1: such as whether or not the instrument has a resonance chamber. Okay,
Speaker 1: so some general rules. Let's say that you've got two strings.
Speaker 1: They're made out of the exact same material, they have
Speaker 1: the same thickness, they are under the same amount of tension,
Speaker 1: but one is longer than the other one. The longer
Speaker 1: of those two strings will produce the lower note when
Speaker 1: you strum them. But if you have two strings that
Speaker 1: are of the same material, they're the same thickness and
Speaker 1: they're the same length, whichever one has more tension on
Speaker 1: it will produce a higher note. It will vibrate at
Speaker 1: a higher frequency, So the tighter string will vibrate faster
Speaker 1: than a looser string. If you have two strings that
Speaker 1: are made of the same stuff, they're the same length,
Speaker 1: they're at the same tension, but they are a different
Speaker 1: thick nous, you've got one that's thicker than the other.
Speaker 1: The thicker string will produce a lower note than the
Speaker 1: thinner string. It will vibrate more slowly. You've got more
Speaker 1: mass there. So on an instrument like a guitar, you
Speaker 1: can have all the strings be the same length right there,
Speaker 1: the same length from nut to bridge, right the top
Speaker 1: of the neck, all the way down to the base
Speaker 1: of the strings. They're all the same, they aren't stopping
Speaker 1: at different points. So on an instrument like a guitar,
Speaker 1: you can have all the strings be the same length
Speaker 1: from the top of the neck down to the very
Speaker 1: base of the strings. All those strings are the same length.
Speaker 1: They stretch the entirety of the fretboard, but each of
Speaker 1: those strings are of a different thickness and a different tension.
Speaker 1: To have each one tuned to a specific frequency a
Speaker 1: vibration that represents a specific note. Tuning a guitar consists
Speaker 1: of adjusting the tension on those strings. So the tuning
Speaker 1: pegs are all about either increasing the tension by turning
Speaker 1: the tuning peg to tighten the string, or decreasing the
Speaker 1: tension by turning the peg the other direction to loosen
Speaker 1: the string. And strings get out of tune over time.
Speaker 1: They may stretch because of the fact that it's a
Speaker 1: you know, elastic material like the nylon strings you might
Speaker 1: find on the ukulele, or it could be environmental factors
Speaker 1: like the temperature or humidity. Those can all affect them.
Speaker 1: When we come back, I've got more to say about
Speaker 1: stringed instruments and how they work, but before we get
Speaker 1: to that, let's take a quick break. There are several
Speaker 1: stringed instruments that have a single fixed string dedicated to
Speaker 1: each note within the instruments range. So a piano is
Speaker 1: a great example. You've got your standard eighty eight notes
Speaker 1: on a typical grand piano. Harps also fall into that
Speaker 1: general category. There are some bode liars that can work
Speaker 1: a little differently, but most harps are the same way,
Speaker 1: where every string is dedicated to a specific note. So
Speaker 1: musicians who play these instruments have to manage way more strings,
Speaker 1: but they don't have to make any big changes to
Speaker 1: those strings. They don't have to alter the strings length
Speaker 1: to produce different notes. They just plug a different string.
Speaker 1: But other stringed instruments like the guitar family, or violins
Speaker 1: or cellos, viola's stuff like that, they require players to
Speaker 1: change the length of the strings by pressing down on
Speaker 1: the neck of the instrument, you know, pinching the string
Speaker 1: and thus changing the anchor points for that string. Changing
Speaker 1: the length of the string changes the strings vibration frequency,
Speaker 1: thus changing the pitch. Guitars have a fretboard, with the
Speaker 1: frets providing that anchor point for the string at specific intervals.
Speaker 1: Makes it really easy. The frets are space such that
Speaker 1: playing an open string and then playing each fret moving
Speaker 1: up the neck toward the body will follow the chromatic scale.
Speaker 1: Each fret is a semi tone apart from the one
Speaker 1: before and the one after it. I can actually demonstrate this.
Speaker 1: I am going to uh play up the scale on
Speaker 1: the G note of my cigar box guitar. So this
Speaker 1: is the open string and the first fret would be
Speaker 1: a half tone or a semi tone up, and then
Speaker 1: the next one and next m Yeah. So just by
Speaker 1: altering the length of the string you have changed how
Speaker 1: frequently it will vibrate and us increase the pitch. If
Speaker 1: you ever ever see anyone doing air guitar and they're
Speaker 1: moving their hand back when the guitar pitch is going up,
Speaker 1: they're doing it wrong. Pianos are similar to guitars in
Speaker 1: the sense that if you play twelve consecutive keys, including
Speaker 1: both the white and the black keys, you play the
Speaker 1: chromatic scale. Each key in sequence is one semi tone
Speaker 1: apart from the one before it and the one that
Speaker 1: comes after it. Bode String instruments like the violin are
Speaker 1: different from instruments like guitars in several important ways. The
Speaker 1: musician plays the instrument by drawing a bow strung with horsehair,
Speaker 1: typically with a coating of rosin on it to increase friction,
Speaker 1: and they draw this horsehair against one or more strings
Speaker 1: on the instrument like a violin violence. By the way,
Speaker 1: you have four strings, a standard guitar has six, and
Speaker 1: when you do this, when you draw the horsehair against
Speaker 1: the string, it causes that string to vibrate. Unlike a guitar,
Speaker 1: the violin and instruments like it don't have a fretboard.
Speaker 1: They have what are called fingerboards, but there are no
Speaker 1: frets on them. Musicians can still change the length of
Speaker 1: strings by pressing down on them, similar to a guitarist,
Speaker 1: but without the frets. It involves learning the relative positions
Speaker 1: of where your fingers need to go on that fingerboard
Speaker 1: and requires a lot of muscle memories that you can,
Speaker 1: you know, replicate notes accurately, wind bode the strings. Vibrations
Speaker 1: transferred to the body of the violin through the bridge
Speaker 1: that's the part at the base of the strings, and
Speaker 1: it goes down into the body of the violin through
Speaker 1: what is called the sound post, which is in the
Speaker 1: resonance chamber. The sound boast is both to transmit vibrations
Speaker 1: from the top of the violin to the the back
Speaker 1: of the violin and make the whole body vibrate and resonate,
Speaker 1: but it's also meant to support the top of the violin.
Speaker 1: There's a lot of pressure on the top of a
Speaker 1: violin because of the tension that's on those strings. The
Speaker 1: sound emerges from holes that are in the top of
Speaker 1: the violin's face. These are called f holes, and the
Speaker 1: resonating body amplifies the sound of the strings significantly. Many
Speaker 1: stringed instruments have resonance chambers which helps amplify and direct sound.
Speaker 1: In fact, the cigar box guitar I was just playing
Speaker 1: has a resonance chamber. That's the box, the actual cigar box,
Speaker 1: and the The luthier who made my cigar box guitar
Speaker 1: has cut a hole in that box so that the
Speaker 1: sound can reson nate outward. If you don't have a
Speaker 1: resonance chamber, then the vibrating strings would be pretty quiet
Speaker 1: and it would be difficult to hear it over other instruments.
Speaker 1: The way you produce vibrations with a stringed instrument, whether
Speaker 1: it's by strumming or plucking or boeing or striking the strings,
Speaker 1: will help shape the sound as well the strings themselves
Speaker 1: and the design of the instrument as a whole. So
Speaker 1: all of these things contribute to the specific overtones that
Speaker 1: are created when you play that instrument. And that's why
Speaker 1: each of those instruments sounds different from the other instruments.
Speaker 1: Whether it's a banjo, guitar, lute, mandolin, harp, piano, violin,
Speaker 1: or whatever. It's the specific qualities of those types of
Speaker 1: instruments that gives each one its own sound. Another thing
Speaker 1: that shapes the quality of the sound is whether the
Speaker 1: strings are doubled. Some instruments double up on strings for
Speaker 1: specific notes, like the mandolin tends to do this. I
Speaker 1: think it was done that way in order to make
Speaker 1: my fingertips cry, but really the more likely original reason
Speaker 1: was it was done to amplify the volume of sound,
Speaker 1: because as instruments got louder, people had to figure out
Speaker 1: ways of making older instruments be able to play along
Speaker 1: with newer, louder instruments. And some of you may be
Speaker 1: wondering why I'm bothering going through all this stuff, and
Speaker 1: it's really just to illustrate that over time, we've really
Speaker 1: learned how to shape instruments so that they can harness
Speaker 1: the power of physics, even before we had a full
Speaker 1: understanding of those physics. And this required an enormous amount
Speaker 1: of trial and error as people learned what did and
Speaker 1: didn't work, and then taught this to younger generations who
Speaker 1: improved upon previous methods while learning more about the actual
Speaker 1: science behind the practice. The reason I went with stringed
Speaker 1: instruments after percussion is that it's pretty easy to get
Speaker 1: your mind wrapped around what is creating the sound, because
Speaker 1: ultimately it's the vibration of those strings. Although those strings
Speaker 1: could be feeding vibrations into some other part of the
Speaker 1: musical instrument, but we can see the strings vibrate, So
Speaker 1: this one's pretty easy to grasp. You know, you see
Speaker 1: it and you're like Oh, that's what's making the noise.
Speaker 1: But what about instruments that you blow into. Well, it
Speaker 1: helps if we continue our division of the instruments into
Speaker 1: their classifications. So I'm going to go with woodwinds next,
Speaker 1: which confusingly also includes instruments like the flute, but more
Speaker 1: on that in a second. First, we know sound ultimately
Speaker 1: relates back to vibration. There are a few different basic
Speaker 1: types of woodwinds that create vibration in different ways, and
Speaker 1: I'll start with read instruments. These instruments typically have a mouthpiece,
Speaker 1: though some double read instruments don't have a full mouthpiece.
Speaker 1: But the instrument has a read, or sometimes two reads,
Speaker 1: and those those reads vibrate when you force air against
Speaker 1: them in a specific uh direction. If you're force sing
Speaker 1: an airstream against them properly, you cause the read to vibrate,
Speaker 1: and as the vibration of that read, that ends up
Speaker 1: causing the oscillations of air pressure that's going into the instrument,
Speaker 1: the fluctuation the wave of air pressure. So the source
Speaker 1: of vibration for these read instruments are the reads themselves.
Speaker 1: That's pretty easy to understand. But what about instruments like
Speaker 1: the recorder? Or the penny whistle or the flute. These
Speaker 1: don't have reads. There's no obvious physical element in the
Speaker 1: instruments that's vibrating. So what is creating the vibrations that
Speaker 1: make the sound. Well, I'll start with the humble recorder,
Speaker 1: which I remember playing way back in middle school, shortly
Speaker 1: after the recorder had been invented. I'm kidding, I'm not
Speaker 1: that old, but my former co host Lauren would have
Speaker 1: made that joke, So this one goes out to her.
Speaker 1: If you look at a recorder, you'll see that below
Speaker 1: the mouthpiece on the body of the recorder is a notch,
Speaker 1: and that notch is a piece that some people call
Speaker 1: the ramp. If you were to cut the recorder in half,
Speaker 1: down the full length of the instrument, you would see
Speaker 1: that the ramp is like this shelf like structure that
Speaker 1: comes to a point, and the point faces the mouthpiece.
Speaker 1: The mouthpiece itself leads to a very narrow passage that's
Speaker 1: called the wind way. It's it's narrow so that it
Speaker 1: forces the wind through a very narrow channel. Blowing into
Speaker 1: the recorder forces air down this wind way. Then the
Speaker 1: air hits the edge of this ramp, and here's where
Speaker 1: the vibration happens. When the stream of air hits that
Speaker 1: sharp ramp, some of the air deflects up out of
Speaker 1: the instrument, so up the ramp like dukes of hazard
Speaker 1: going off the highway. Some of the air, though, continues
Speaker 1: into the air column that's inside the recorder's body, the
Speaker 1: bore of the recorder, so it continues forward, and the
Speaker 1: oscillation of the jet of air is what creates the
Speaker 1: basic vibration within the recorder. It's the source of the sound.
Speaker 1: I'll get to what's going on in the body of
Speaker 1: woodwinds in a minute, because that bit is standard across
Speaker 1: the board to some extent. But first I want to
Speaker 1: chat about how a flute creates vibrations. Now, when I
Speaker 1: say flute, I'm specifically referring to transverse or side blown flutes.
Speaker 1: If you were to look at the mouth hole for
Speaker 1: the flute, you would see it has a sharp edge.
Speaker 1: This acts very much like the ramp in a recorder.
Speaker 1: So if you blow down properly on the mouthpiece, you
Speaker 1: create an edge tone. The frequency for the main edge
Speaker 1: tone depends upon the velocity of the stream of air
Speaker 1: and the distance from the air stream to the edge,
Speaker 1: so with a recorder, this would mean changing the length
Speaker 1: of the wind way, which you can't really do because
Speaker 1: it's a physical structure. But with a flute you can
Speaker 1: actually do that. You can roll the flute so it's
Speaker 1: a little closer to your lips or a little further away,
Speaker 1: and you can actually shape the edge tone that way.
Speaker 1: This becomes important because by varying both the velocity of
Speaker 1: the air dream and the distance between the edge and
Speaker 1: the lips, a flow disc can vary the flute pitch.
Speaker 1: This is called overblowing. But to understand that, it's time
Speaker 1: we talk about what's going on inside all these different
Speaker 1: instruments once the oscillating air molecules are in there. So
Speaker 1: think of a cross section of a woodwind instrument. Imagine
Speaker 1: we can visualize what's happening inside of it. And let's
Speaker 1: think of flutes and recorders, because these are types of
Speaker 1: open ended tubes like a pipe you would use in plumbing.
Speaker 1: If you were to stop up the end of the instrument,
Speaker 1: you would have a closed ended tube. And something interesting
Speaker 1: happens that I'll get to in a moment. Now. Before
Speaker 1: we play our recorder or our flute, the air inside
Speaker 1: the instrument is at a pressure that's equivalent to the
Speaker 1: ambient atmospheric pressure. That is, the pressure inside a recorder
Speaker 1: or an oboe, or a clarinet or a flute. It's
Speaker 1: the same as the air pressure inside the room. And
Speaker 1: it's like that as long as it's not being played.
Speaker 1: As soon as you start blowing into the instrument, you're
Speaker 1: introducing waves of increasing and decreasing air pressure. Those fluctuations
Speaker 1: that were caused by the read and the read instrument,
Speaker 1: or the ramp of a recorder or the mouthpiece of
Speaker 1: the flute, for example. At either end of instruments like
Speaker 1: the flute or recorder, you have the anti noodes. Now,
Speaker 1: remember when I was describing standing waves. The anti noode
Speaker 1: is where you get the big fluctuations and amplitude. So
Speaker 1: at the anti noode you've got low air pressure and
Speaker 1: maximum movement of air so velocity uh so. And this
Speaker 1: is all with respect to atmospheric pressure in the center
Speaker 1: of this air column. So in the center of the
Speaker 1: bore of your flute, let's say, in between the anti
Speaker 1: noodes that are at the ends, you've got the node.
Speaker 1: This is an area of high air pressure and very
Speaker 1: low or no velocity with respect to atmospheric pressure. So
Speaker 1: this is the opposite of what we saw with stringed instruments,
Speaker 1: because with those is really easy for us to imagine right,
Speaker 1: the anchored points at either end of a string are nodes.
Speaker 1: They cannot move right, so they're locked in place. The
Speaker 1: bits that wobble about on the string are further in
Speaker 1: from those points. That's where the anti noode is. It's
Speaker 1: very easy to visualize, but with an instrument like a
Speaker 1: flute or recorder, that lockdown part is actually in the middle.
Speaker 1: It's in between the anti noodes. The ends of the
Speaker 1: air column are the parts oscillating, and the bit in
Speaker 1: the middle is remaining an equilibrium. This is actually how
Speaker 1: the air column inside the instrument is vibrating, and the
Speaker 1: frequency of that vibration determines the fundamental frequency or tone
Speaker 1: we hear coming from that instrument. So this column of
Speaker 1: air inside the instrument is vibrating many times per second.
Speaker 1: If we were doing this with a recorder, we would
Speaker 1: start with all the holes on the recorder covered right,
Speaker 1: so we don't have any holes uncovered. This creates the
Speaker 1: maximum length bore for the recorder blowing into the mouthpiece
Speaker 1: of the record or would force an air stream against
Speaker 1: the ramp, which would create this oscillating effect that would
Speaker 1: start the vibration pattern down the bore of the recorder.
Speaker 1: Somewhere near the center of the bore would be the
Speaker 1: note where the air pressure is that the highest and
Speaker 1: the air velocity is at its lowest. The vibration would
Speaker 1: create the note we hear played by the recorder. But
Speaker 1: what if we open up one or more of those
Speaker 1: holes that we've covered up. Well, if you do that,
Speaker 1: you're decreasing the length of the air column, just as
Speaker 1: pressing down on the guitar's fretboard effectively reduces the length
Speaker 1: of the vibrating string and increases the frequency or pitch.
Speaker 1: So the holes in a recorder aren't quite big enough
Speaker 1: to have an open hole completely cut off the air
Speaker 1: column at that point, But that ends up getting a
Speaker 1: little too deep into the physics of recorders. Basically, if
Speaker 1: you have a recorder or a penny whistle and you blow,
Speaker 1: as you start to lift fingers off the holes from
Speaker 1: the far end and you move up the instrument, you'll
Speaker 1: hear the notes in increasing in pitch as you do so.
Speaker 1: By taking your thumb off the thumb hole on the
Speaker 1: underside of the recorder. You divide the air column into
Speaker 1: two parts, which means you get two notes inside the recorder,
Speaker 1: not just one. And the vibration the frequency has increased
Speaker 1: again because those air columns are shorter, just as if
Speaker 1: you had a shorter string vibrating. So you get to
Speaker 1: you a second register of notes in the recorder. With
Speaker 1: a really well designed recorder, you can get up to
Speaker 1: four registers or thirty notes playable on an instrument with
Speaker 1: just eight holes, which is pretty amazing. And it's all
Speaker 1: because of the physics of these standing waves of air
Speaker 1: pressure inside the instrument. Now, when we come back, I'll
Speaker 1: explain how instruments like the clarinet and the oboe are
Speaker 1: very different from this. But let's take a quick break now.
Speaker 1: Not all would wind instruments fall into the cab story
Speaker 1: of open tube physics. Some like the clarinet and the
Speaker 1: obo are closed tubes. Uh, and obo's and saxophones actually
Speaker 1: get a little more complicated. They actually fall into conical
Speaker 1: pipe designation. That's going to get a little too deep
Speaker 1: into it. We're gonna stick with closed tubes. So the
Speaker 1: major difference from a physics perspective on these instruments is
Speaker 1: how those standing waves form inside the bore of the instrument.
Speaker 1: So with a flute, we learned that the ends of
Speaker 1: the instrument are where the antinodes are, where the point
Speaker 1: of maximum oscillation in regard to air velocity is, and
Speaker 1: with the node or the equilibrium point inside the boar
Speaker 1: of the instrument. A closed ended pipe has a node
Speaker 1: at the closed end, and this makes sense. It's like
Speaker 1: the anchor point for a guitar string, like at the
Speaker 1: nut of the guitar, So the mouthpiece would represent the
Speaker 1: closed end of the pipe and the node uh would
Speaker 1: be there with respect to velocity. This also means that
Speaker 1: the harmonics of a closed pipe system are different from
Speaker 1: an open pipe system. To really get into all of
Speaker 1: this would require way more physics and math than worked
Speaker 1: well for an audio podcast. But really the important thing
Speaker 1: to remember is that the nature of the tube of
Speaker 1: the bore, whether it's open or closed or conical, is
Speaker 1: going to affect how those standing waves form inside the instrument,
Speaker 1: and the way the standing waves form affects the different
Speaker 1: types of overtones the instrument is capable of producing when played,
Speaker 1: so you get a very different tone out of a
Speaker 1: clarinet or an oboe than you would with a flute
Speaker 1: or recorder. And part of that is because the harmonics
Speaker 1: that a clarinet or oboe can create are very different
Speaker 1: because of the nature of those standing waves than the
Speaker 1: harmonics you get out of a flute or a recorder.
Speaker 1: I'm sure all that's clear is mud right. Well, if
Speaker 1: nothing else, remember that the length of the column of
Speaker 1: air is inversely proportional to the frequency of the sound
Speaker 1: you produce. The longer the column of air is, the
Speaker 1: lower the frequency will be, and thus the lower pitch
Speaker 1: of note you will produce. And just as we talked
Speaker 1: about with stringed instruments like the harp or piano, which
Speaker 1: have strings dedicated to specific notes, there are read instruments
Speaker 1: that fall into that kind of category too. For example,
Speaker 1: the harmonica harmonicas have brass reads in them. It's the
Speaker 1: vibration of those reads that produce the notes you hear
Speaker 1: when someone plays harmonica, and the lengths of the reads
Speaker 1: determine the frequency of vibration. A longer read is going
Speaker 1: to vibrate more slowly. It's going to take longer for
Speaker 1: a full oscillation to happen than a shorter read, and
Speaker 1: so a longer read will produce a lower note. Moreover,
Speaker 1: harmonicas actually have two plates of reads, so if you
Speaker 1: were to take harmonica apart, you would find under the
Speaker 1: top plate you would find a read late. This would
Speaker 1: be a plate that has typically brass reads mounted on it.
Speaker 1: The next layer down would be a structure called the comb.
Speaker 1: This is a notched structure. It directs the air blown
Speaker 1: into the harmonica or drawn through the harmonica to the
Speaker 1: appropriate reads. Below the comb is a second read plate.
Speaker 1: This is the draw read plate. So blowing into the
Speaker 1: harmonica activates the top read plate, and drawing air through
Speaker 1: the harmonica activates the lower red plate. And you have
Speaker 1: ten holes that you can blow into with your standard harmonica.
Speaker 1: So if you choose hole number one and you blow
Speaker 1: into it, you're gonna get one note as the air
Speaker 1: is directed to the upper read plate and makes that
Speaker 1: read vibrate. If you breathe in, you will get a
Speaker 1: different note because it's going to pull air in and
Speaker 1: direct it to the lower read plate and it will
Speaker 1: vibrate that read. Now, typically the draw note is the
Speaker 1: next one up on the scale from the blown note.
Speaker 1: So if the blow note for a whole one in
Speaker 1: your harmonica is a C. The draw note for a
Speaker 1: whole one is probably a D. Harmonicas tend to have
Speaker 1: ten holes, so you get twenty notes. Pretty nifty. Let's
Speaker 1: move on to talk about brass instruments. So with woodwinds,
Speaker 1: we're producing vibrations to create those standing waves using either
Speaker 1: reads or in the case with the flute or the recorder,
Speaker 1: by using an edge that deflects part of the airstream.
Speaker 1: But with brass instruments, the source of vibration comes from
Speaker 1: something else. It comes from the lips of the person
Speaker 1: who is playing the instrument. So the player presses their
Speaker 1: lips against a mouthpiece. The mouthpiece position depends upon the instrument.
Speaker 1: Some instruments require more of a centered placement, others require
Speaker 1: more of a two thirds placement. It all depends on
Speaker 1: the specific instrument you're looking at. And the player forces
Speaker 1: air through their lips and they keep enough tension on
Speaker 1: their lips to create a buzzing vibration, and this is
Speaker 1: what creates the fluctuating wave of air that goes down
Speaker 1: the tube of this instrument and ultimately produces the musical note.
Speaker 1: The use of the lips has a specific name, and
Speaker 1: it's the umbature, and it gets pretty complicated, well beyond
Speaker 1: just the buzzing I described, and it brings into stuff
Speaker 1: like the tongue and the teeth and the face muscles
Speaker 1: and everything that's needed to create specific types of buzzing
Speaker 1: in order to produce specific notes. Because by altering the umbashure,
Speaker 1: a player can get different notes out of a brass instrument,
Speaker 1: even if that instrument has no valves or pitch control.
Speaker 1: So a bugle, like a typical bugle, is an example
Speaker 1: of such an instrument. If you look at a bugle,
Speaker 1: you'll notice that it doesn't have any keys or valves
Speaker 1: or a slider or anything like that. In fact, you
Speaker 1: could uncurl a bugle and you would end up with
Speaker 1: a really long horn and no controls for it. And
Speaker 1: you might think that because you have an instrument that
Speaker 1: you can't change the length of you know, we were
Speaker 1: talking about with woodwinds that by pressing the keys or
Speaker 1: by moving your fingers off of holes you shorten that
Speaker 1: air column. Well, this is an instrument where you can't
Speaker 1: do that. You can't change the length of the air
Speaker 1: column in it. So if you can't change the length
Speaker 1: of the air column in it. How can you change
Speaker 1: the frequency? How can you play different notes on an
Speaker 1: instrument like that? Well, it's done by altering the umberature.
Speaker 1: By adjusting air flow and tension, players can change the
Speaker 1: vibrational frequency of their buzzing lips so the bugle will
Speaker 1: only resonate at specific frequencies those harmonics we've talked about before.
Speaker 1: So through this alteration and vibration, a bugle player can
Speaker 1: sound a bugle along a certain sequence of notes the
Speaker 1: harmonics for that instrument. Typically, bugle plays can get five
Speaker 1: different notes. Really good bugle players might be able to
Speaker 1: get a sixth note, and they're all based on the
Speaker 1: fundamental frequency of the bugle. Interestingly, the actual fundamental frequency
Speaker 1: of the bugle itself. The first harmonic is too low
Speaker 1: for bugle players to play because it would require a
Speaker 1: lip vibration that's too slow to replicate. So the lowest
Speaker 1: note a bugle player can aim for is the second harmonic.
Speaker 1: If you've listened to my previous episode on the subject,
Speaker 1: you know that to learn the second harmonic you take
Speaker 1: the frequency of the first harmonic and you multiply it
Speaker 1: by two, right, you just it's all whole integers. So
Speaker 1: This means the second harmonic is the same note as
Speaker 1: the first harmonic, but it's an octave higher. Most bugle
Speaker 1: players can play the second, third, fourth, fifth, and sixth harmonics,
Speaker 1: so five notes, and most bugle calls only consist of
Speaker 1: those five notes. Expert players might be able to get
Speaker 1: out the seventh harmonic as well, for a total of
Speaker 1: six notes, but it's not easy to do. The specific
Speaker 1: notes depend upon the bugle, but most bugles I know
Speaker 1: of are in the key of B flat, and typically
Speaker 1: it's treated as if it were a C C and
Speaker 1: B flatter fairly close to each other, so you can
Speaker 1: kind of fudget a little bit. Now, all brass instruments
Speaker 1: use ummature alterations as part of how to produce different notes,
Speaker 1: but in order to produce even more sounds, people got
Speaker 1: really clever and inventive, and that's what leads us to
Speaker 1: instruments that have valves or other methods of pitch alteration.
Speaker 1: So let's go with valves first and talk about instruments
Speaker 1: like the trumpet, which I should add was the whole
Speaker 1: inspiration for me to do this episode in the first place.
Speaker 1: Was I sat down and said, how the heck does
Speaker 1: a trumpet make so many different sounds with just those
Speaker 1: three keys. Because I'm not a musician, I never went
Speaker 1: had banned, so I just didn't know how that worked.
Speaker 1: So if you look at a trumpet, you'll see that
Speaker 1: it has those three valves. You know, there's three pistons
Speaker 1: that you can push down, and those valves give the
Speaker 1: player the same effect as if they can magically change
Speaker 1: the length of the trumpet. Each valve, when depressed, opens
Speaker 1: up a section of tubing for air to flow through.
Speaker 1: It's adding more sections for air to travel through, thus
Speaker 1: expanding the length of the air column, and that means
Speaker 1: the frequency of the vibration of that air column has
Speaker 1: to decrease because as the length increases, the frequency decreases,
Speaker 1: and so the pitch goes down. Assuming that the player
Speaker 1: is maintaining a stable umbature. Will get to that, and
Speaker 1: that last part is really important if you play a
Speaker 1: trumpet in a stable way, so you're not changing the
Speaker 1: vibrational frequency of your lips as you're playing. You can
Speaker 1: get seven different notes by using the valves in various combinations.
Speaker 1: So if you were depressed the second valve the middle one,
Speaker 1: you would go a half step down from the trumpet
Speaker 1: just being played naturally. Pressing the first valve down is
Speaker 1: one whole step down from the scale, and then you
Speaker 1: could press them in various combinations to go down another
Speaker 1: sequence of semi tones. But like the bugle player, the
Speaker 1: trumpet player can change their umbature and increase or decrease
Speaker 1: the frequency with which their lips are vibrating and thus
Speaker 1: produce higher or lower notes respectively. Then use the valves
Speaker 1: to in effect change the length of the trumpet and
Speaker 1: thus play way more notes than you could play if
Speaker 1: it were like a bugle, and changing the length of
Speaker 1: the instrument changes the resonant frequency. Remember, the horn is
Speaker 1: only going to produce sounds at the harmonics in the
Speaker 1: key for that horn, but pressing down a valve and
Speaker 1: opening up a new pathway for air to flow through
Speaker 1: lengthens the horn, so you change the horns harmonics. It's
Speaker 1: like the trumpet just grew a few inches, which affects
Speaker 1: the frequencies it can produce. This is even easier to
Speaker 1: understand with the troumba. Own Like trumpet players, trombone players
Speaker 1: can play different notes by changing the umberature, but they
Speaker 1: can also use the slide on the trombone to physically
Speaker 1: lengthen the air column inside the instrument. Sliding the slide
Speaker 1: out lengthens the overall instrument. Thus it lengthens the overall
Speaker 1: path for the air to go through, it lowers the
Speaker 1: frequency or note. Pulling the slide back decreases the length
Speaker 1: of the path and increases the frequency or pitch. So
Speaker 1: by changing both umbature and the slide position, a trombone
Speaker 1: player can play many notes. They can even change their umbature,
Speaker 1: move the slide out, and play a higher note than
Speaker 1: the one they had been playing, because again they've changed
Speaker 1: the vibrational frequency of their lips. By increasing that vibrational frequency,
Speaker 1: they're playing a higher note even though they're moving the
Speaker 1: slide out at around the same time. It's a really
Speaker 1: complicated thing, and it makes me just respect musicians even
Speaker 1: more than I already did, because they're like freaking magicians.
Speaker 1: So it all comes down to how can I use
Speaker 1: this thing to create sounds that please people using vibrations
Speaker 1: in clever ways. That's the basics of all instruments. I'm
Speaker 1: endlessly impressed with the incredible ingenuity we humans have had
Speaker 1: in making different musical instruments. To take advantage of these
Speaker 1: elements of physics that I talked about, and I hope
Speaker 1: that this episode was interesting to you and that you
Speaker 1: get a deeper appreciation and understanding of how musical instruments
Speaker 1: work and how they produce these sounds. There are tons
Speaker 1: of amazing videos and articles about musical instruments online. I
Speaker 1: highly recommend if you want to learn more, to be
Speaker 1: very specific in what you're searching for. For example, if
Speaker 1: you want to learn more about how trumpets work or
Speaker 1: how guitar harmonics work, doing a quick search online is
Speaker 1: going to pull up tons of resources and give you
Speaker 1: a deeper understanding. I consider this more of an overview because,
Speaker 1: as I said, to really get into it quire a
Speaker 1: series all on its own, and honestly I should leave
Speaker 1: that to somebody who has far more expertise than I do.
Speaker 1: But I hope that you've enjoyed this. If you guys
Speaker 1: have any suggestions for future episodes of tech Stuff, you
Speaker 1: can reach out to me on Facebook or Twitter. The
Speaker 1: handle we use is text stuff HSW, so I will
Speaker 1: look out for your messages there and I'll talk to
Speaker 1: you again really soon. Y. Text Stuff is an I
Speaker 1: Heart Radio production. For more podcasts from My Heart Radio,
Speaker 1: visit the I heart Radio app, Apple podcasts, or wherever
Speaker 1: you listen to your favorite shows.