Musical Instruments

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• Musical Instruments
• Contents
• What is the difference between high and low
  notes?
• Why do different instruments sound different?
• What does it mean to play out-of-tune?

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What is Pitch?
SIM Pitch/Beat Freq
SIM Pitch/Beating Freq
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Pitch depends on length!Which trombone has the
longer wavelength? Higher pitch?A
B
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Do nodes or antinodes appear at the mouthpiece?
Bell?
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Tillery, Physical Science
Do nodes or antinodes appear at the open ends of
these pipes? Which pipes produce the longer
wavelength? Which pipes produce higher pitch?
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Musical instruments create vibrations of the air
to produce pitches.
Wind instruments vibrate the air with either a
reed or a musicians buzzing lips.
String instruments vibrate the air with a metal
or plastic string.
SIM Open/Closed Pipe
SIM Both ends fixed
Trumpet Tuba Flute Sax Clarinet Oboe Trombone
Guitar Piano Violin Viola Harpsichord
SIM both ends open
SIM 1 end open and 1 end fixed
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The Soundry available at http//library.thinkques
t.org/19537/
Harmonics - the frequencies that are multiples of
a waves fundamental frequency. Ex if the
fundamental frequency is 440 Hz, the harmonics
are 880 Hz, 1320 Hz, etc.
Timbre - a musical instruments unique sound.
Ex a clarinet doesnt sound like a trumpet
because it has a different timbre. An
instrument's timbre is due to the relative
intensities of harmonics present in its tone.
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Harmonic Series
1st
4th
2nd
5th
3rd
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Along with the 1st harmonic, a wave from a
CLARINET has lots of the 3rd, 5th, and 7th
harmonics, while only a little of the 2nd, 4th,
and 6th harmonics. Along with the 1st harmonic,
a wave from a TRUMPET has lots of the 3rd, while
only a little of the 2nd, 4th, and 5th harmonics.
SIM Composite Wave
The Soundry available at http//library.thinkques
t.org/19537/
9
Tillery, Physical Science
When two instruments are each playing a slightly
different pitch they sound out of tune.
(SIM1) (SIM2)
Beating Frequency the wavering sound heard when
two slightly different pitches are played
together Beating Frequency f1 - f2