1. Sound Quality Chapter 21 Sect. 4

2. Sound Quality warm-up: textbook p. 626 Passages 1 and 2 (all Q’s)

3. Sound Quality
/watch?v=XMZW4Ol5zLk
Today, I can describe the difference between noise and music

4. Sound Quality: Resonance (rez-O-nunce)
(review)
Resonance occurs when two objects naturally vibrate at the same frequency.
The wave (sound) produced by one of the objects causes the other object to vibrate.

5. Sound Quality: Interference
Interference the combination of two or more waves that result in a single wave. (positive or negative)
ex: a sonic boom
Sound Quality the result of the blending of several pitches (frequencies) through interference.
ex: musical instruments have pleasing sound quality if operated properly

6. Sound Quality: Resonance and Musical Instruments
Musical instruments use resonance to make sounds.
String instruments  strings vibrate & send waves inside the hollow instrument body, where it is amplified
Wind instruments  blowing air causes mouthpiece vibrations … resulting sound waves are amplified inside the tubes/pipes
Percussion instruments  make sounds when struck … different sizes & materials have different pitches

7. Strings
p. 619

8. Winds
p. 620

9. Percussion
p. 621

10. Sound Quality: Noise
Noise is any sound (especially non-musical) that is a random mix of frequencies (pitches) … shows no regular pattern
Music shows distinct repeating patterns

11. Music vs. Noise