Short for module. A compact type of computer file, originally developed on the Amiga, that plays back audio files when loaded into a MOD player. MOD files are a cross between MIDI and digital audio files, and containing both digital samples and playback instructions that tell the player which notes and samples to play, i.e., MOD files also include a user-defined group of digitized instrument sounds that are used to play the music. Basic MOD files contain just four tracks of 8-bit mono audio data: various sampling rates are used; the data can be compressed; and, each track can trigger any one of up to 31 samples from the MOD file for four-voice polyphony. Each instrument can have its own volume, and a few simple effects are included, such as echo and pseudo-reverb (achieved by repeating notes), tremolo, and pitch-bend. Most MOD files are in the .STrK format, but there are other file formats such as .S3M. There is a recent trend toward 8-channel MOD players, threatening compatibility.
mod wheel : See modulation wheel.