Unit 2.1

Question 1

Instrument sounds (how they differ)

Answer 1

• material they’re made out of
• shape
• how it’s played
• how the air moves through it

Question 2

Coupled acoustics

Answer 2

In most musical instruments, there are two vibrating devices
- one generates the sound wave
- the other is coupled to it (and amplifies it)
Ex. violin - strings generate, body amplifies

Question 3

Tones

Answer 3

1. edge tones (ex. flute)
2. reed tones (ex. clarinet, trumpet, voice)

Question 4

Resonator

Answer 4

coupled to the basic device (ie. hollow tube, air chamber)
- certain instrument parts like to amplify certain instruments (timbre)

Question 5

Spectral centroid

Answer 5

How the amplitudes of different overtones are distributed
- center of gravity
- review image

Question 6

Resonance

Answer 6

bands of high energy enhanced by the structure of a sound medium
- helps identify specific instruments

Question 7

String instruments (& sympathetic resonance)

Answer 7

some have continuous supplied energy (ie. violins)
SR = when something vibrates because something vibrating near it is vibrating at that resonant frequency (not direct stimulation)

Question 8

Woodwinds and Brass instruments

Answer 8

• vibration produced in mouthpiece sets a column of air resonations
• flared bell - radiates higher overtones (sounds bright)
• longer pipes - radiates lower/deeper tones

Question 9

Percussion instruments

Answer 9

• receives energy in short bursts
• parts vibrate at their natural frequency, but travel to other parts of the instrument leading to many non-harmonic frequencies
• some, not all have resonators