Here is a huge collection of midi files that were rescued before Geocities was taken down, In total, over 51,000 songs are located in this collection, spanning the full 1995-2009 lifetime of Geocities:
https://archive.org/details/archiveteam-geocities-midi-collection-2009 (https://archive.org/details/archiveteam-geocities-midi-collection-2009)
Below is ver 1.2 of the collection:
https://archive.org/details/TheGeocitiesMidiCollectionVersion1.2 (https://archive.org/details/TheGeocitiesMidiCollectionVersion1.2)
Cool, are they public domain?
Most definitely not. You can be sure that the last thing teenagers creating Geocities websites in the mid-90s cared about was copyright (and of course Public Domain is a concept that doesn't exist in many jurisdictions). You'll find tons of MIDI files ripped from games, recreations of commercial music, etc... in there, so a lot of material for which the site owners probably didn't even have the permission to upload them.
bummer :(
i wanted to remix them but im sure even if some are original content their contact info is missing forever so it's pretty much impossible to ask for permission
Ya I guess not knowing the copywrite status of each midi file in the collection could be a problem as well as not having the contact info of each composer/artist and many of the midi's are compositions of commercial copyrighted music. I'm somewhat of a digital hoarder, so I often fail to look at those things. Despite all these issues, no one seems to care about this collection as no one has requested archive.org (http://archive.org) to take it down and it is a fairly well known midi collection on the internet.
Here is a BBS CD called "DR. MUSIC, CDXPRT" by Aces Research, Inc., published in 1993, it is a Music software and Midi, CMF, ROL, MOD, WAV, VOC and SND collection CD for BBS's. I own a physical copy of this CD which I purchased in 1993 or 1994 at Radio Shack if I am remembering right. They have archived a digital copy of this CD which is downloadable from their website:
https://archive.org/details/drmusic (https://archive.org/details/drmusic)
I am not sure how they are able to legally distribute this CD as a digital download.