1. Why musical instruments have characteristic sounds
A Sound Idea
Why musical instruments have characteristic sounds

2. Waves - their properties
wavelength
frequency
speed
shape
type (longitudinal or transverse)
polarity (if transverse)

3. Wavelength, Frequency & Speed
Speed = Wavelength x Frequency
If wave crests are 3 metres apart and
the wave is travelling 12 metres every second,
then 4 wave crests will pass every second.
wavelength = 3 metres
wave speed = 12 metres per second
frequency = 4 hertz

4. Wave types - Longitudinal &Transverse
Longitudinal - e.g. Sound
Transverse - e.g. Sea, Light
Wave motion is in the same direction as the wave is travelling
Wave motion is at right angles to the direction in which the wave is travelling

5. Wave Shapes - Sine, Sawtooth & Square
All waveshapes can be created by adding together a series of sine waves whose wavelengths are exact fractions of the fundamental wavelength which means their frequencies are exact multiples of the fundamental frequency

6. Waves - Combining Sine Waves 1

7. Waves - Combining Sine Waves 2

8. Waves - Combining Sine Waves 3

9. Waves - Combining Sine Waves 4

10. Waves - The Violin String
Various modes of vibration
Each end cannot move
Any wavelength such that an exact number of half waves = the length of the violin string is possible

11. Waves - The Clarinet Various modes of vibration
The air at the reed end cannot move
The air at the bell end can move
Any wavelength such that an odd number of quarter waves = the length of the clarinet is possible

12. Waves - The Real Violin

13. Waves - The Real Clarinet

14. Waves - The Numbers
An Octave is a doubling of frequency = a halving of wavelength
A Fifth is an increase in frequency of 50% = a reduction of wavelength by 33%
A Third is an increase in frequency of 25% = a reduction of wavelength by 20%

15. ... and now it's time to
WAVE
goodbye!