Baldi’s Basics uses MIDI music, but the creator of the game converted all the music to WAV files. I was able to re-create them all, so they’re exactly the same, but reverted to MIDI again.
Downloads:
MIDI files – http://www.mediafire.com/folder/ye1g9yurorct9/
Soundfont – http://www.mediafire.com/file/77ubeyz550m0uq8/
Programs used:
Video editor – Adobe Premiere Pro
MIDI creator – Aria Maestosa
Speaker recorder – Audacity
Screen recorder – Fraps
MIDI player – Synthesia