Sound waves and music

Musical instruments are designed to produce relatively pure sound waves with large amplitudes. There are several different approaches:

• you have seen standing waves set up on a string already ...
• one can also create standing waves in a flat surface, such as the membrane of a drum or the body of a bell
• one can create standing waves of air molecules within a tube, as in a clarinet, flute, or trumpet

Let's look at this last mechanism in some detail ...

• Using propane and flames to make sound waves visible
• A flute drives the flames
• Sound waves produced by air columns

Now, on to some more general properties of sound waves in air.

• Physical characteristics of sound waves

What happens if two instruments play simultaneously, but don't QUITE produce the same frequency?

• Beats -- when waves with different frequencies meet

For more information

• Flute acoustics: an introduction shows how complicated the real sound created by a musical instrument can be.
• A Fourier synthesis applet allows you to add together harmonics of a fundamental wave and both see and hear the wave form.

Copyright © Michael Richmond. This work is licensed under a Creative Commons License.