The old websites sometimes maintained selections of MIDI music, which they would link or use as embeds in battles. I will do the same, and I'm going to store MIDIs I've either salvaged from the Internet Archive or found by searching their filenames here. Additionally, I'll make note of any files that are known to have existed but that I don't have copies of. E-mail me if you have any of these...
MIDIs will be sorted by site, and those that have been found by searching the filename will be marked with an *. There is no guarantee these are the right song. Lost MIDIs will be named but lack links, and instead have the filename next to the on-site title if they're different. MIDIs will be presented in the order they were in if there was an index on the original site, or otherwise, will be presented alphabetically.
I don't claim to own anything here and these MIDIs are stored and documented for historical purposes only. Many of the recovered midis were found in this repository. If you know anything about any of these songs' origins, including the artists who converted them to MIDI, please contact me with that information so I can add it.
battlesong.mid: Pokémon Red/Blue - Trainer Battle. The humble battlesong.mid appeared fairly early in Pokébattles Red, and appeared in
battle2.mid*: Unknown origin. May not be the right song.
Adelante.mid: "Adelante!" by Sash (sequenced by Eddie Wong).
"Pokémon" - see "battlesong.mid".
Flame Version had relatively good documentation on its MIDI files to begin with and I've preserved it.
Breath of Fire
Chrono Cross Boss Music - ccboss.mid
(Note: "Final Fantasy II" here refers to the US release of the game later rereleased as Final Fantasy IV.)
Parasite Eve Battle Music - pebattle.mid