Impulse Tracker Modules

Impulse Tracker modules (.it files) are an audio format that Roblox used to support. Unlike other formats, IT files are module files which are structured differently to normal sound recordings. The format belongs to Impulse Tracker. Roblox stopped supporting IT files sometime in late 2019. As a result, attempting to link a to an IT file asset will no longer work as it will display the message ("unsupported file format") instead. 
Only administrators were able to upload .IT files to the platform. There are only two known IT file assets on the platform, which were uploaded by : Wind of Fjords and TheGreatStrategy. At some point, the audio assets were deleted, most likely due to the format being unsupported.
Roblox also supported the playback of similar formats, like .MOD, .XM and .S3M, as well as MIDI. They were similarily seldom used.
== Advantages ==
The benefit to tracker music is that the file size is much smaller compared to MP3 or OGG, at the cost of flexibility and ease of use. This was useful when internet download speeds were much slower in the early 2000s than they are today.
== Bugs ==
Roblox's sound engine, FMOD, had an imperfect music tracker implementation. Some problems include:
*Any module played would loop forever, even if the 'Looped' checkbox was unticked.
*Any module playing would never stop, even when told to do so in code. The only way to stop a song from playing would be to close the Roblox client entirely.
* In older versions of Roblox Studio, songs would still continue to play when the reset button was pressed. When the game was run again, modules would begin playing on top of each other. The only way to stop a tracker file from playing was to restart Roblox Studio.
*Every time a module loops, the music tracker does not reset the effects applied upon each channel. This causes subsequent loops of the song to sound different from the first.
*The music tracker erroneously allows BPMs lower than 32. This is what causes the long sustain near the end of 'Wind of Fjords.'
==References==