Amplitude Modulation (AM)
AM and FM
AM and FM are actually Vibrato (FM) and Tremolo (AM), but with the modulation being in the audio range. If you'd normally use a LFO for Vibrato, for FM a "regular" oscillator is used.
FM refers to any frequency modulation, for examples on FM look here.

The AM examples below are by BlueHell:



Last Updated ( Monday, 19 June 2006 )
 
AM and RM
AM and RM are closely related:



Last Updated ( Sunday, 29 January 2006 )