There is a special track that plays in the "Worship Room" of the Dark Sanctuary with the Wafers and the petrified Organikk, but it's neither listed in the mus folder where most tracks are provided, nor does it seem to be documented anywhere on this page. Would there be any way it could be added to the Hidden Music Tracks page?
I hope you didn't check each file one by one looking for it...
It's Hymn. Known as church_hymn.ogg in the mus folder. You wouldn't recognize it because it plays slower AND gets random speed-ups and skips.
I looked into it. The track doesn't change in speed, only in pitch. Here's loosely what happens:
The track starts playing from it's halfway point at 0.5 (half) pitch.
The track plays in "sections". Each section lasts a random amount of time:
- 60% of the time, it lasts 2 seconds.
- 20% of the time, it lasts 3 seconds.
- 20% of the time, it lasts 4 seconds.
At the end of each section, the track randomly chooses a new timestamp and starts playing from there. It cannot pick a time in the first 2 seconds of the track or the last 6 seconds of the track.
Every three sections, the track changes the current pitch by a random amount between -0.1 and +0.1, down to a minimum of 0.4 and up to a maximum of 0.6.
Every time there's a change in timestamp or pitch, there's a transition period where the "old" music fades out and the "new" music fades in. This only lasts one frame.