Each module file format builds on concepts introduced in its predecessors. ; The MOD format (.MOD) : The
MOD format was the first file format for tracked music. A very basic version of this format (with only very few pattern commands and short samples supported) was introduced by Karsten Obarski’s
Ultimate Soundtracker in 1987 for the
Amiga. It was designed to use 4 channels and fifteen samples. Ultimate SoundTracker was soon superseded by
NoiseTracker and
Protracker, which allowed for more tracker commands (effects) and instruments. Later, variants of the MOD format that appeared on the Personal Computer extended the number of channels, added
panning commands (the Amiga’s four hardware channels had a pre-defined stereo setup) and expanded the Amiga’s frequency limit, allowing for more octaves of notes to be supported. : Arguably one of the most widespread tracker formats (also due to its use in many computer games and demos), it is also one of the simplest to use, but also only provides few pattern commands to use. ; The Oktalyzer format (.OKT) : This was an early effort to bring eight-channel sound to the Amiga. Later replayers have improved on the sound quality attainable from these modules by more demanding mixing technologies. ; The MultiTracker format (.MTM) : Produced by American Demoscene group Renaissance, MultiTracker brought up to 32-channel sound to the PC tracker community. Songs that took full advantage of the 32 simultaneous channels were extremely taxing to typical computers of the era. ; The MED/OctaMED format (.MED) : This format is very similar to sound/pro/noisetracker, but the way the data is stored is different.
MED was not a direct clone of SoundTracker, and had different features and file formats.
OctaMED was an eight-channel version of MED, which eventually evolved into OctaMED Soundstudio (which offers 128-channel sound, optional synth sounds, MIDI support and many other high-end features). ; The AHX format (.AHX) : This format is a synth-tracker. There are no samples in the module file, rather descriptions of how to synthesize the required sound. This results in very small audio files (AHX modules are typically 1k–4k in size), and a very characteristic sound. AHX is designed for music with
chiptune sound. The AHX tracker requires
Kickstart 2.0 and 2 Mb RAM memory. ; The ScreamTracker 3 format (.S3M) : The
Scream Tracker 3 S3M format added sample tuning (defining the exact frequency of the
middle C for samples), increased the number of playback channels, made use of an extra column specifically for volume control (which was extended by other trackers to handle panning commands as well), and compressed pattern data for smaller file sizes. , playing a FastTracker 2 module called
Dead Lock, composed by tracker musician Elwood in 1995 ; The FastTracker 2 format (.XM) : With the
XM format,
FastTracker 2 introduced the concept of "instruments", which applied volume and panning envelopes to samples. It also added the ability to map several samples to the same instrument for multi-sampled instruments or drum sets. XM uses instrument-based panning – instrument numbers in patterns always reset the channel’s panning to the current sample's initial panning. It uses MOD effect command letters, plus a few of its own for more sound control. The composer can define initial tempos and speeds; provide envelopes to samples by assigning them to instruments; set sample looping and apply automatic sample vibrato oscillation. ; The Impulse Tracker format (.IT) :
Impulse Tracker introduced the
IT format, which, in comparison to the XM format, allows instruments to also specify the transposition of assigned samples depending on the note being played, applying resonant filters to samples, and defining “New Note Actions” (NNAs) for instruments to release playing notes on a pattern channel while a new note is already playing, which helps to keep the number of pattern channels to while still being able to have a high polyphony. Like S3M files (and contrary to XM files), panning is channel-based, meaning that channels have an initial pan position which can be overridden by panning commands or instruments’ and samples’ default panning settings. == Scene ==