Doom music

All of Doom's music was composed by Robert Prince. There are 23 distinct tracks present across the original 3 episodes, with Thy Flesh Consumed not introducing any new tracks.

Unsourced attributions should not be added here. The information below is based on "word of God" from Bobby Prince or other reliable sources.

Trivia
"Hiding the Secrets", which is present twice in the IWAD, exists in two slightly different versions: "Demons on the Prey", which is present thrice in the IWAD, exists in two slightly different versions: "Intermission from Doom", which is present twice in the IWAD, exists in two slightly different versions: "Waltz of the Demons", which is present twice in the IWAD, exists in two slightly different versions:
 * The D_E1M7 and D_E2M5 version of "Demons on the Prey" has a cymbal instruction in bar 7 that has a wrong Legato instruction that causes the note to play at the very start of the song in some MIDI players. This is never heard in-game, and the D_E3M5 version of the song doesn't have this issue.
 * The D_E1M9 version of "Hiding the Secrets" has a broken silence in Track 10 (percussion) that causes the drums to come in at the very first bar, and play 1 bar early for the rest of the song in some MIDI players. This never happens in-game, and the song plays normally regardless. D_E3M9 does not have this issue, and will play correctly in any instance.
 * "Waltz of the Demons" is the only one with an audible difference in-game: the bass string instrument that comes in at about 10 seconds in is quieter in D_E2M7 than in D_E3M7. (MIDI channel volumes of 80 and 100, respectively.) The other songs have slightly different MIDI data between versions, but nothing that causes a difference in the way they are played.