Here's the list of files I've found on various servers (all of these links work; if you click one and it fails, it's because of the filename, I'll fix any problems before the page goes live), along with the newspost that originally talked about it. There is some overlap with the list of stuff you posted in your google drive doc - this provides context for all of the overlap, as well as fleshes out the list.

There are still a number of runs to be made, through the various sources of info, but this is a decent beginning.

Initials after files are prolific creators - AG = Archie Gates, BS = Bryan Simon, SM = Sean Mortensen, SB = SilverBrin.

Files that are included on compilation pages already are not in this list.

http://halo.bungie.org/misc/nsinger_halotunes.html
http://halo.bungie.org/misc/patriarch917_music/
http://halo.bungie.org/misc/mothergoat_halotunes.html
http://halo.bungie.org/misc/sm_afoa_ost/
http://halo.bungie.org/misc/sm_ghostsofonyx.html
http://halo.bungie.org/misc/P3PP3RM4N_music/

That said - here's what I found today.

http://files5.bungie.org/Halo_FallFromAbove(YouCan'tStop)_OC_ReMix.mp3
http://halo.bungie.org/n/9271

http://files5.bungie.org/alwyswin.mp3
http://halo.bungie.org/n/10942

http://files5.bungie.org/RunFromMe.mp3
http://halo.bungie.org/n/9362

http://files5.bungie.org/halorap.mp3
http://halo.bungie.org/n/12589

http://files5.bungie.org/Mathom - Warthog Driver.mp3
No newspost - originally from RoosterTeeth

http://files5.bungie.org/Palette-SwapNinja_HaloAllIPlay-Oh.mp3
http://halo.bungie.org/n/25735

http://files.bungie.org/02-BrandonStrader-Halo3-Memoriam-DoD.mp3
http://halo.bungie.org/n/34928

http://files.bungie.org/007_last_stand.mp3 (SM)
http://halo.bungie.org/n/20102

http://files.bungie.org/a_walk_in_the_woods_rfinal.mp3
http://halo.bungie.org/n/7444

http://files.bungie.org/all_the_worlds_problems.mp3 (BS)
http://halo.bungie.org/n/23957

http://files.bungie.org/Arrival.mp3 (SM)
http://files.bungie.org/We_Go_Feet_First.mp3 (SM)
http://halo.bungie.org/n/19560
(different from Arrival here:
http://halo.bungie.org/misc/sm_afoa_ost/ )

http://files.bungie.org/banhammer.mp3 (BS)
http://halo.bungie.org/n/24067

http://files.bungie.org/bloodgulchblues.mp3
http://halo.bungie.org/n/7152

http://files.bungie.org/BlowMeAway-instrumental.mp3
http://halo.bungie.org/n/33638

http://files.bungie.org/can_my_mom_have_recon.mp3 (BS)
http://halo.bungie.org/n/24205

http://files.bungie.org/Can_You_Feel_The_Lag_Tonight_Mix_v2.mp3
http://halo.bungie.org/n/35181

http://files.bungie.org/dont_make_us_kick_your_ass.mp3
http://halo.bungie.org/n/12610

http://files.bungie.org/edgen_halo_master_and_chief.mp3
http://halo.bungie.org/n/8213

http://files.bungie.org/edgen_halo_ruined_desert.mp3
http://halo.bungie.org/n/6656

http://files.bungie.org/edgen_halo_the_heretic.mp3
http://halo.bungie.org/n/15599

http://files.bungie.org/edgen_halo.mp3
http://halo.bungie.org/n/5377

http://files.bungie.org/edgen_halo2.mp3
http://halo.bungie.org/n/5615

http://files.bungie.org/eigenhat_reach_Siege.mp3
http://halo.bungie.org/n/30237

http://files.bungie.org/Fahordlingrads.mp3
http://halo.bungie.org/n/12613

http://files.bungie.org/Five_Long_Years_Pt_1.mp3
http://files.bungie.org/Five_Long_Years_Pt_2.mp3
http://files.bungie.org/Halo_3_Recon.mp3
http://halo.bungie.org/n/24190

http://files.bungie.org/Halo_Reach_Stats_Theme.mp3 (SB)
http://halo.bungie.org/n/31396

http://files.bungie.org/Gumpel_recital.mp3
http://halo.bungie.org/n/13169

http://files.bungie.org/H2hiphop.mp3
http://halo.bungie.org/n/8019

http://files.bungie.org/Halo_3_Musical_Battle.mp3
http://halo.bungie.org/n/23858

http://files.bungie.org/Halo-Electronica.mp3 (SB)
http://halo.bungie.org/n/5547

http://files.bungie.org/HaloMonkMix.mp3
http://halo.bungie.org/n/10171

http://files.bungie.org/HaloTheResistance.mp3
http://files.bungie.org/Programmedtokill.mp3
http://halo.bungie.org/misc/BestOfHalo.mp3
http://halo.bungie.org/n/9135

http://files.bungie.org/Harvest_Suite.mp3 (SM)
http://halo.bungie.org/n/19375

http://files.bungie.org/i_bought_my_50.mp3 (BS)
http://halo.bungie.org/n/23882

http://files.bungie.org/Mahdrigalo.mp3 (SB) http://halo.bungie.org/n/5078

http://files.bungie.org/Mahdrigalo2.mp3 (SB)
http://halo.bungie.org/n/5649

http://files.bungie.org/Master_Chief_Suite.mp3 (SM)
http://halo.bungie.org/n/19742

http://files.bungie.org/Mombasa.mp3
http://halo.bungie.org/n/7509

http://files.bungie.org/my_new_home.mp3 (BS)
http://halo.bungie.org/n/24149

http://files.bungie.org/Needler_Walk.mp3 (AG)
http://halo.bungie.org/n/13328

http://files.bungie.org/oneshot_on_my_x.mp3 (BS)
http://halo.bungie.org/n/23920

http://files.bungie.org/Parabolic_Lemonade_Failure.m4a
http://files.bungie.org/Parabolic_Lemonade_Failure.mp3
http://halo.bungie.org/n/10984

http://files.bungie.org/Parting_Ways.mp3 (SM)
http://halo.bungie.org/n/19523

http://files.bungie.org/Shrike_-_Halo_The_MC.mp3
http://halo.bungie.org/n/9721

http://files.bungie.org/snipers_are_wussies.mp3 (BS)
http://halo.bungie.org/n/24174

http://files.bungie.org/Ultrash_-_Halo_The_Miracle.mp3
http://halo.bungie.org/n/9832

http://files.bungie.org/Ultrash_Halo_Resistance-RMX.mp3
http://halo.bungie.org/n/10494

http://files.bungie.org/videogamepianist_mjolnirmix.mp3
http://halo.bungie.org/n/12763

http://files.bungie.org/vote_for_bungie.mp3 (BS)
http://halo.bungie.org/n/24125

http://files.bungie.org/xenophobic_alien.mp3
http://halo.bungie.org/n/33046

http://files3.bungie.org/Beautiful_Needler.mp3 (AG)
http://files3.bungie.org/Sound_of_Needler.mp3 (AG)
http://halo.bungie.org/n/12618

http://files3.bungie.org/Detroit_Starrzz_-_Halo_-_Radio_Edit_96_MP3.mp3
http://halo.bungie.org/n/29378

http://files3.bungie.org/in_halo_3.mp3
http://halo.bungie.org/n/20029

http://files3.bungie.org/killingspree.mp3
http://halo.bungie.org/n/31241

http://files3.bungie.org/snow_halo.mp3
http://halo.bungie.org/n/16617

http://files3.bungie.org/WhiteButtonThug.mp3
http://halo.bungie.org/n/16147

http://files5.bungie.org/06b-unforgotten-siege.mp3
http://halo.bungie.org/n/15727

http://files5.bungie.org/micks.mp3
http://halo.bungie.org/n/15706

http://files5.bungie.org/brysi_encore.mp3 (BS)
http://halo.bungie.org/n/25700

http://files5.bungie.org/get_backsmacked.mp3 (BS)
http://halo.bungie.org/n/25526

http://files5.bungie.org/girlgameronmyfl.mp3 (BS)
http://halo.bungie.org/n/25238

http://files5.bungie.org/gold_bars_make_you_rich.mp3 (BS)
http://halo.bungie.org/n/25057

http://files5.bungie.org/grifball_ftw.mp3 (BS)
http://halo.bungie.org/n/24514

http://files5.bungie.org/halo_dos.mp3
http://halo.bungie.org/n/17723

http://files5.bungie.org/halo_in_the_end.mp3
http://halo.bungie.org/n/13982

http://files5.bungie.org/Halo3MPRapFinal.mp3
http://halo.bungie.org/n/20500

http://files5.bungie.org/his_name_is_snipedown.mp3 (BS)
http://halo.bungie.org/n/25442

http://files5.bungie.org/i_wanna_be_an_mlgpro.mp3 (BS)
http://halo.bungie.org/n/24798

http://files5.bungie.org/i_wont_teabag.mp3 (BS)
http://halo.bungie.org/n/25324

http://files5.bungie.org/if_i_worked_at_bungie.mp3 (BS)
http://halo.bungie.org/n/24580

http://files5.bungie.org/mc_under_my_tree.mp3 (BS)
http://halo.bungie.org/n/24779

http://files5.bungie.org/Needler_Song_4.mp3 (AG)
http://halo.bungie.org/n/13932

http://files5.bungie.org/nobody_loves_me.mp3 (BS)
http://halo.bungie.org/n/25471

http://files5.bungie.org/OpenLettertoH3Players.mp3
http://halo.bungie.org/n/20482

http://files5.bungie.org/pd_Heretic.mp3
http://halo.bungie.org/n/15778

http://files5.bungie.org/rh_playing_halo_odst_remix.mp3
http://halo.bungie.org/n/25045

http://files5.bungie.org/rocket_race_is_for_noobs.mp3 (BS)
http://halo.bungie.org/n/24877

http://files5.bungie.org/roy_lunchbox.mp3 (BS)
http://halo.bungie.org/n/26014

http://files5.bungie.org/the_song_for_bks.mp3 (BS)
http://halo.bungie.org/n/27089

http://files5.bungie.org/unchosen_mjolnirsong.mp3
http://halo.bungie.org/n/17366

http://files5.bungie.org/under_cover.mp3
http://halo.bungie.org/n/24971

http://files5.bungie.org/unforgotten.mp3
http://halo.bungie.org/n/18676

http://files5.bungie.org/walshy.mp3 (BS)
http://halo.bungie.org/n/25872