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3.3.1
WHAT’S A
MUSICAL
INSTRUMENT,
ANYWAY?
The voice was certainly the first musical instrument, followed by
percussion instruments, then melodic instruments, then chordal
instruments.
Musical instruments are probably as old as modern humans. At
least a couple of hundred thousand years old, in all likelihood.
Possibly much older.
So,
what’s a musical instrument?
All musical instruments are resonators, or resonating machines.
A resonator is a contraption (in this case, all or part of a musical
instrument) that vibrates in sympathy with (i.e., as a result of similar
vibrations of) another nearby part of the instrument that you set in
motion.
So,
with most musical instruments (not all, as you’ll see), two different things
vibrate:
• The initial sound source that you, the musician, set in motion,
and
• A resonating body connected to the first sound source.
Any given resonator vibrates more readily or efficiently at certain
characteristic frequencies, called resonant frequencies, than at other
frequencies. Musical instrument designers shape instruments to resonate best at
certain frequencies, and damp the others as much as possible. That’s why
trumpets, French horns, and saxophones are shaped so differently.
A
few of the variables that determine the instrument’s resonant frequencies and,
therefore, the instrument’s overall sound, include:
• Size of the instrument
• Shape of the instrument
• Material the instrument is made of
• Internal construction of the instrument
Your brain responds best to the uncomplicated vibrations that
simple shapes generate. Simply shaped soundmakers create tones
that you can make sense of. If you strip away frets and valves and
tuning mechanisms from musical instruments, you find that they
have pretty simple shapes compared with other soundmakers in
nature, such as your average poplar tree or Niagara falls, which
generate noise instead of pure tones.
3.3.2
SETTING
RESONATORS IN
MOTION,
DIRECTLY AND
INDIRECTLY
You can get sound
out of a musical instrument’s resonator in two ways.
1. The Direct Way
You
can simply whack it. Clobber, shake, or otherwise beat the dang thing directly.
For instance, when you hit a drumhead, causing it to vibrate, you also set the
body of the drum (the resonator) vibrating, because it’s fixed securely to the
drumhead.
• With some instruments, such as cymbals and gongs, you
strike the resonator directly. The resonator is the instrument.
• With others, such as marimbas, you use mallets to hit tuned
wood bars, causing the bars to vibrate. Underneath each
wood bar, a resonator in the shape of a tube vibrates in
sympathy, producing a dominant fundamental frequency that
you recognize as a specific tone or note.
Instruments
such as these—the ones you hit directly—do not sustain sound for very long
(except for tuned percussion instruments such as the xylophone family,
kettledrums, and steel drums). So, if you want to create a continuous stream of
sound, you have to keep delivering blows (e.g. a snare drum roll).
2. The Indirect Way
You can set
into vibration a certain part of the instrument other than
the resonator. The part that you set in motion connects to the
resonator via an intermediary of some sort, which transmits the
original vibrations to the resonator, which vibrates in sympathy.
With
a stringed or wind instrument, unlike most drums, you can sustain the sound
pretty easily. The string or reed that you set in motion has much less mass than
the resonator to which it is indirectly attached. So you don’t need to deliver
too much energy to keep the string or reed or your lips vibrating, and thus the
resonator vibrating in sympathy.
(In the case of the flute family of instruments, you blow across a
sharp edge. The resulting turbulence creates an air reed which sets the
column of air inside the flute vibrating, which causes the body of the flute—the
resonator—to vibrate in sympathy.)
In general ...
• A small resonator
(e. g., hi-hat or flute) creates small, fast compressions and rarefactions that
your brain perceives as high frequencies of sound—high pitch.
• A large, heavy resonator
(e. g., bass drum or acoustic bass), moves big masses of air, creating big, slow
compressions and rarefactions of air molecules which stimulate your ears and
finally your brain, which perceives low frequencies of sound—low pitch.
3.3.3
CATEGORIES OF
MUSICAL
INSTRUMENTS
When most musicians think of categories of acoustic musical
instruments, three come immediately to mind: strings, winds, and
percussion.
That’s
pretty close to the formal system developed by Erich von Hornbostel and Curt
Sachs, which has served as the classification standard since 1914. Their system
divides acoustic instruments into four categories:
• Idiophones: percussion instruments without a membrane
• Membranophones: percussion instruments with a membrane
• Aerophones: wind instruments, including the human voice
• Chordophones: stringed instruments
An additional category is now generally recognized:
• Electrophones: instruments that produce sound electronically
3.3.4
IDIOPHONES:
PERCUSSION
INSTRUMENTS
WITHOUT A
MEMBRANE
All cultures have idiophones. But not all cultures have
membranophones. Australian aboriginal percussion instruments, for
example, consist of idiophones but not membranophones.
It’s
likely idiophones were the first non-vocal musical instruments. Probably rocks
(the first rock music). But knocking two rocks together doesn’t make much sound
because rocks have too much mass to vibrate and resonate much.
Pieces of wood work better. Bones work even better, especially
hollow bones. Hollow leg bones. And skulls. Human skulls.
You can make numerous other nifty idiophones from various
bones. For instance, you can fashion a rattle using spine bones and a cord.
Idiophones include:
• Rattles
• Cymbals
• Bells
• Xylophones
• Steel
drums (they do not have membranes, like other drums)
• Musical saws
• Gongs
• Washboards (yeee-ha!)
Playing the Musical Saw: Why and How
A few years ago, in an interview with an admiring
reporter from the Dodge City Musical Saw
Weekly, Marshal McDillon explained how and
why he plays the musical saw.
“So you’ve been
riding the trail all day, and you finally set up camp and take care of the
horses and eat some beans and roast some squirrels. And later on, everybody’s
sitting around, poking at the fire with willow switches, and somebody pulls out
a mouth organ. Or, if nobody has one, then mouth organ music just comes out of
thin air and everybody looks at each other, puzzled-like. It’s a cliche of every
Classic Western, the mouth organ music coming out of thin air around the
campfire. You’re supposed to act like you don’t even hear that mouth organ
music.
“Anyhow, when this
happens, I just head on over to the chuck wagon and find a hand saw and a fiddle
bow.
“I sit down on a log
and clamp the handle of the saw between my knees so that the saw points straight
up and the teeth face towards me.
“Next, I grab the
top of the saw with my left hand and bend it to my left into a ‘C’ shape, then
slightly back at the top so that it makes a slight ‘S’ shape.
“Then I pick up the
bow with my right hand and let ‘er rip. When I bow the bent saw, it makes a
howling sound. Like a coyote. Or a theremin. No discrete pitches like you get
with a piano.
“It’s hard to play
it good enough so that it doesn’t sound like a heartbreakingly lonesome wild
animal.
“But I’d recommend
to everybody that, before you try this out on the trail, you may wish to
practice in the privacy of a dark windowless cellar. Give yourself some time to
get the hang of it. Say, four or five years.”
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3.3.5
MEMBRANOPHONES:
PERCUSSION
INSTRUMENTS
WITH A
MEMBRANE
The first
membranophone was probably a drum fashioned from an animal skin stretched over
something conveniently hollow. Maybe the skull of somebody the drummer didn’t
particularly like. (If your band has a drummer, watch out.)
Membranophones include:
• Nearly all drums
• Marimbas
• Kazoos,
including the venerable comb and tissue paper. New York’s Julliard School offers
a four-year comb and tissue paper (CATP) degree program with a classical music
emphasis. San Francisco’s UC Berkeley has a six-year CATP program that focuses
on jazz.
3.3.6
AEROPHONES:
WIND
INSTRUMENTS,
INCLUDING THE
VOICE
Here’s how
aerophones work:
• You blow into the instrument, setting a reed (or reeds)
vibrating (woodwinds, saxes, harmonicas).
OR
You blow into the instrument while buzzing your lips (brass
instruments).
• A column of air (the intermediary) inside the instrument
transmits the vibrations of the reed(s) or your lips to the
resonator, such as the body of a saxophone or trumpet.
• The resonator, being much more massive than the reed(s) or
your lips, amplifies the vibration of the reed(s) or your lips.
Aerophones include:
• Brass instruments
• Woodwinds
• Flutes, recorders, penny whistles
• Harmonicas (the
harmonica is easily the best instrument to play at night around
the campfire, to drown out the sound of the musical saw)
• Reed pipes
• Accordions, concertinas, etc.
• The
voice
As for your voice, air pressure serves as the power supply, the
same as in other aerophones:
• You take a breath and, as you let it out, the air pressure sets
your vocal folds (also called vocal cords) vibrating.
• A column of air (the intermediary) inside your respiratory
tract, elevated in pressure, transmits the vibrations of your
vocal folds to several resonators: the hard cartilage of the
trachea (windpipe) and bronchial tubes in your chest, the
bones of your rib cage, your pharynx (throat), and the various
bones in your head.
• These resonators, being much more massive than your vocal
folds, amplify the vibrations of your vocal folds.
(The
above is a rough description. There’s no unanimous agreement on precisely how
everything happens in the production of human vocal sound.)
The consonants and other sounds you require for speech and
singing depend on how you position your tongue and shape your
oral cavity.
Evolution of String Players and Brass Players
Why can’t they get
along?
According to a
survey of Glasgow-based symphony orchestra musicians, here’s how string players
view brass players:
• Slightly oafish and uncouth
• Heavy boozers
• Empty vessels
• Like to be in the limelight
• Loud-mouthed and coarse
• Don’t
practise
And here’s how brass
players view string players:
• Like a flock of bloody sheep
• Precious
• Overly sensitive and touchy
• Humourless
• Think
they’re God’s gift to music
• A bunch of weaklings
As if that weren’t
bad enough, in 2004, the string section of the Beethoven Orchestra of Germany
went to court to get more money than the brass players. The string players
argued they deserved higher pay because they play more notes than the brass
players.
Perhaps a Ph. D. candidate in search of an
interesting research project could devise a
method for testing the implied hypotheses of the
Glasgow musicians: that brass players evolved
from drunken oafs, and string players evolved
from humourless sheep.
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3.3.7
CHORDOPHONES:
STRINGED
INSTRUMENTS
Chordophones include all stringed instruments, not just instruments
that you can play chords on.
Chordophones work like this:
• You pluck, bow, or hammer the string(s), setting the string in
motion.
• A bridge (the intermediary) transmits the vibration of the
string to the resonator, such as the body of a guitar or fiddle,
or the soundboard inside a piano.
• The resonator, being much more massive than the string,
amplifies the vibration of the string(s).
Some important chordophones are:
• Guitars, banjos and other lute-type instruments
• Harps (Celtic, concert, etc.)
• String
section instruments: violin, viola, cello, double bass
• Pianos (the
piano is often mistakenly thought to be a percussion
instrument because hammers hit strings)
• Zithers
3.3.8
ELECTROPHONES:
INSTRUMENTS THAT
PRODUCE
SOUND
ELECTRONICALLY
If a musical instrument does not require electricity to produce its
sound, you can almost always classify it as an idiophone,
membranophone, aerophone, or chordophone.
After that, it gets tricky.
Keyboard instruments in which sounds are produced wholly by
electronic oscillators are practically always considered
electrophones.
Nailing down what other kinds of instruments constitute
electrophones poses all sorts of problems:
• An electric guitar is usually considered a chordophone. But
whether that would apply to purely digital electric guitars is
contentious.
• Same applies to other instruments that look like acoustic
instruments, or something like acoustic instruments, but
produce sound by digital means, and may or may not mimic
the sounds of acoustic instruments.
• Technically,
samplers and turntables would be considered electrophones, even though much of
the “sound of origin” is acoustic.
• Electronic
devices used for sound generation, sound processing, and sound playback are
widely “played” live by musicians, and would never previously have even been
considered musical instruments—mixers and computers, for example. Here, the line
between musical instruments and electronic sound shapers or processors gets
infinitely fuzzy.
