We can enjoy music and at the same time have very little knowledge of Its production. Let us imagine we are in a concert hall listening to an orchestra. What are the various steps in the process which begins with each player playing his instrument and ends with our enjoyment of listening to the resultant sounds?

Sounds as physical phenomena fall mainly into two classes: tone and noise. All sounds have their physical origin in vibratory motion of some sort. If the vibratory motion is irregular and relatively complex, what we hear is "noise". If the motion is regular and relatively simple, the result is called "tone". In addition, a very important part is played in music by the absence of sound — silence.

Sound travels as a compression wave through solids, liquids and gases. It cannot travel through a vacuum because there is nothing there to compress.

We hear sound when our ear-drums are made to vibrate under the influence of disturbances in the air around us. The human ear is an extremely sensitive detector of sound waves. It changes the pressure pulses into nerve impulses which are transmitted to the brain, where the sound is eventually heard.

The physical properties of any tone are: 1. frequency (so many vibrations per second), 2. harmonic structure, 3. amplitude of vibration, and 4. duration. In musical discussions, these properties are usually talked about as pitch, tone-colour (or timbre), dynamics and rhythm, respectively.