MOD player: play and convert tracker modules.

At a glance

What a module is, and why converting one is not simple

A tracker module is not a recording. It is a set of short samples, a bass note, a snare, a chord stab, plus patterns: grids of rows that say which sample to play on which channel at which pitch, with effect commands for slides, vibrato, arpeggios and volume. The format came from the Commodore Amiga in 1987, where four hardware channels and half a megabyte of memory were all there was, and it carried the music of a generation of games, demos and keygens in files of a few dozen kilobytes. The sound only exists when a player runs those patterns, and every tracker's player had its own arithmetic and its own bugs, which composers then wrote around. Play an old module in a generic player and a slide lands a little flat or an arpeggio stutters differently from how its author heard it.

That is why this page does not use one general-purpose engine. Each format goes to a port of the program it was made in. Four-channel MODs are played by the replayer from pt2-clone, a re-creation of ProTracker 2.3D that includes a model of the Amiga's Paula sound chip. XM files, and MODs with six or more channels, go to ft2play, a port of Fasttracker 2.09's replayer. IT files go to it2play, a port of Impulse Tracker 2.15's, and S3M files are played the way Impulse Tracker imports them. All three are by Olav Sørensen (8bitbubsy), who ported the original trackers' own code line by line; the page shows which one took your file.

How to use it

Drop the file. It is rendered from start to finish, usually in a second or two, and then plays in an ordinary player bar you can seek in. The title is shown with the channel count, the number of patterns and the length. Under it is the sample and instrument text: module authors used those name fields for credits, greetings and contact details, so it is often a small letter from 1993. Choose a format and press "Convert and download". MP3 at 320 kbps plays on anything; WAV or FLAC keeps every sample exactly for editing or archiving.

Changing the sample rate renders the song again at that rate, from the patterns, rather than resampling the audio. For four-channel MODs there is also a stereo width setting. An Amiga sent channels one and four entirely to the left speaker and two and three entirely to the right, which is striking on speakers and tiring on headphones; 20% is the pt2-clone default and keeps a sense of space, and 100% is the real machine.

Things worth knowing

A module has no length: most loop for ever. The player notes each position in the song as it reaches it and stops when the song is about to go somewhere it has already been, so you get exactly one pass. A song that loops inside a single pattern cannot be told apart from a long pattern-loop effect and runs to a 20-minute limit; the page says so when that happens.

Tuning follows the hardware. A four-channel MOD is played as a PAL Amiga plays it, where the note written as A comes out at 436.4 Hz, a little under concert pitch; Fasttracker and Impulse Tracker files are at 440. The mix is taken before the trackers' own 16-bit clipping, so a loud module keeps its peaks instead of having them flattened, and if it passes full scale the whole song is turned down to peak at -1 dBFS, with the amount shown.

What it will not play: IT files with more than 100 samples or 200 patterns (Impulse Tracker's own limits, which some files made in later editors exceed); the AdLib FM instruments a few S3M files use, which are silent; MODs with 5, 7 or 9 channels; and other formats such as MTM, 669 or MED. Titles and sample text keep plain ASCII only, because the files' DOS and Amiga character sets do not map cleanly onto a web page.

Credits

The replayers are open source under the BSD 3-Clause licence, copyright Olav Sørensen; their licence texts are served with the player. ProTracker 2 clone and Fasttracker 2 clone are both catalogued on Recomp, a directory of software re-creations, along with MilkyTracker and Schism Tracker if you want to write modules rather than play them. To play ordinary music files in a period-correct player instead, there is Webamp.