FM Synthesis

FM stands for frequency modulation. FM was originally developed within radio technology, but we can use FM to make music as well. FM synthesis is used in many synthesizers, and in a number of sound cards for computers.

How does FM work?
If we change a tone's frequency slowly up and down, we get vibrato. It sounds like this.

What happens if we vary the frequency and make it faster? We get completely new and interesting sounds! Like this, for example.

Values that may be set:
The frequency determines the average frequency of a tone. This also controls the pitch.
The index determines how much the frequency will swing up and down and affects how "sharp" the sound is.
The C:M ratio also affects the timbre.
The amplitude controls the volume.

Here are sounds that have been made with FM synthesis:
Plinglyd
Bell sound