1. Sound Quality Chapter 21 Sect. 4

2. Sound Quality warm-up: textbook p. 626 Passage-2 all Q’s … 1-2-3

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

4. Sound Quality: Resonance (rez-O-nunce)
(from Monday’s lesson)
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.
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