Music

Soundtracks
Mary's Magical Adventure uses a "soundtrack" system; There are three soundtracks in the game that can be switched between in real time by changing Options (F4) > Sound > Soundtrack.

The two soundtracks are Normal and Chiptune; Normal is the intended soundtrack for the game, containing Impulse Tracker songs, usually original compositions for the game, though some may come from video games as placeholders. This soundtrack is the default, so change to the chiptune soundtrack or mute the music to avoid potential copyright claims and strikes on YouTube.

The last soundtrack is comprised of chiptune versions of Mary's Magical Adventure's original songs made using Famitracker with the VRC6 expansion chip. This soundtrack is louder than the normal soundtrack, so adjusting the volume is suggested before changing to this soundtrack. The file the chiptune soundtrack gets its music from is a file located in the Music folder of mma_extra.pk3 named NESMUSIC.nsf.

The "Slot" System
Similar to Sonic Robo Blast 2, Mary's Magical Adventure handles music differently than the game it's based on, Doom, instead opting for a "slot" system. Each song in Mary's Magical Adventure is associated with a number, like 1 is "The Nightlife". To change the music, ACS script 254 is given a number which, depending on your soundtrack, will choose an internal music "lump" within that soundtrack's array. You can hear these songs in-game by bringing down the console (~) then typing puke 254 #, where # is a music ID. If you type an unknown ID, you'll get an error about a song named after a random texture not existing.