This list is under VERY heavy construction.

ULTIMATE MOBILE MUSIC PLAYER omissions

One of the most celebrated features of beatmania IIDX ULTIMATE MOBILE, SOUND VOLTEX ULTIMATE MOBILE, and DanceDanceRevolution ULTIMATE MOBILE by KONAMI was the MUSIC PLAYER, which lets you play thousands of music tracks from various BEMANI titles from the past 22 years of the series' history.

However, quite a few tracks are missing, possibly far more than you'd think at first glance.

For the sake of simplicity, this list will only cover the vanilla versions of BEMANI albums that are specifically on the ULTIMATE MOBILE releases, or were made for the releases. It will not cover V-RARE or special edition releases.

DanceDanceRevolution and SOUND VOLTEX are not currently covered on here, as their ULTIMATE MOBILE releases haven't come out; their lists will be updated accordingly upon their releases.

The BEMANI series with OST releases are not represented on the ULTIMATE MOBILE services at all:

beatmania
Dance Maniax
KEYBOARDMANIA
ParaParaParadise

beatmania IIDX

beatmania IIDX ORIGINAL SOUNDTRACKS (1999)

Original track number: 27 tracks (25 game length, 2 longs)
ULTIMATE MOBILE track number: 6 tracks (6 game length, no longs)
Removed: 21 songs have been removed. This includes 9 of 10 beatmania crossovers (e-motion the one exception), two songs each from Keiichi Ueno and Larry Dunn (and the longs of the latter's songs), and all four songs from Hiroshi Watanabe. In addition, LUV TO ME (disco mix) and Prince on a star are missing due to vocal licensing issues.

BeatStream

TBA

GITADORA

GUITAR FREAKS ORIGINAL GAME SOUNDTRACK (1999)

Original track number: 24 tracks (12 game length, 5 long, 6 BGM tracks, 1 special track)
ULTIMATE MOBILE track number: 18 tracks (12 game length, 5 long, no BGM tracks, 1 special track)
Removed: All six BGM tracks have been removed.

jubeat

jubeat ORIGINAL SOUNDTRACK (2009)

Original track number: 28 tracks (26 game length, 1 long, 11 BGM tracks)
ULTIMATE MOBILE track number: 8 tracks (no longs)
Removed: All eight songs composed/arranged by either Mutsuhiko Izumi or Y&Co., as well as 11 BGM tracks composed by Izumi.

jubeat ripples ORIGINAL SOUNDTRACK (2009)

Original track number: 29 tracks (15 game length, 2 long, 11 BGM tracks)
ULTIMATE MOBILE track number: 11 tracks (10 game length, 1 long, no BGM tracks)
Removed: All five songs composed/arranged by either Mutsuhiko Izumi or SILKY F, as well as 11 BGM tracks composed by Izumi.

jubeat ripples APPEND SOUNDTRACK (2010)

Original track number: 14 tracks (6 game length, 7 long, 1 bonus track)
ULTIMATE MOBILE track number: 10 tracks (5 game length, 4 long, 1 bonus track)
Removed: All four songs composed/arranged by Mutsuhiko Izumi.

pop'n music

pop'n music original soundtrack (1999)

Original track number: 24 tracks (13 arcade originals, 1 BEMANI crossover, 5 CS songs, 2 longs, 3 BGM tracks)
ULTIMATE MOBILE track number: 19 tracks (9 arcade originals, 1 BEMANI crossover, 5 CS songs, 1 long, 3 BGM tracks)
Removed: Four songs previously removed from pop'n music due to vocal licensing issues (YOUNG DREAM, Baby, I'm yours, what i want, FUNKY TOWN '75), as well as Theme of staff roll ~nostalgic live mix~.

pop'n music 2 original soundtracks ★ new songs collection (1999)

Original track number: 34 tracks (14 arcade originals, 13 CS songs, 7 longs)
ULTIMATE MOBILE track number: 21 tracks (6 arcade originals, 11 CS songs, 4 longs)
Removed: 13 songs are removed. Eight of them are songs from pop'n music 2: I'm on fire, Love Is Strong To The Sky (and its long), LOVE FIRE, SAYONARA (and its long), what i want (EURO MIX), はばたけ、ザ・グレートギャンブラー, 光の季節 (and its long), and すてきなタブーラ. Two CS songs are removed as well: Miracle Moon(お月さまが中継局) and R.C..

pop'n music 3 V.S. pop'n stage (2000)

Original track number: 52 tracks (13 arcade originals, 17 pop'n stage songs, 8 CS originals, 4 longs, 2 instrumentals, 3 special tracks, 5 BGM tracks)
ULTIMATE MOBILE track number: 38 tracks (5 arcade originals, 14 pop'n stage songs, 6 CS originals, 3 longs, 2 instrumentals, 3 special tracks, 5 BGM tracks)
Removed: 14 songs removed. Eight of them are from pop'n music 3: LA LA LA, peppermint, TILL THE END OF TIME, un-Balance, 愛を探そう, 恋のシャレード (and its long version), なんか変だ！, and 水中家族のテーマ. Two CS songs were also removed: Candy Blue and Dynamics. Three songs from pop'n stage were also removed: A LOVE WE NEVER KNEW, BoaBoaLady!, and White day dream.

pop'n music 4 arcade originals (2000)

Original track number: 33 tracks (25 game length, 3 longs, 5 BGM)
ULTIMATE MOBILE track number: 20 tracks (25 game length, 3 longs, 5 BGM)
Removed: 13 songs from pop'n music 4 were removed: Girls Riot, Joy!, Nanja-Nai (and long), Over The Rainbow, WE TWO ARE ONE (despite being on an earlier OST), 時代を変えてくTeenage, 君を壊したい, 恋は天然, 透明なマニキュア (and long), 妖怪Zの唄, and 夢そうてい.

pop'n music 4 consumer originals (2000)

Due to the redundancy of both of pop'n music 4's soundtracks having shared the same arcade songlist originally, KONAMI only kept the CS originals on the 4 consumer originals album for MUSIC PLAYER. As such, the track number only reflects the CS songlist from 4.
Original track number: 13 tracks (10 CS songs, 3 longs)
ULTIMATE MOBILE track number: 10 tracks (8 CS songs, 2 longs)
Removed: Concertare and ヤバイオンナ (and its long) have been removed.

pop'n music 5 arcade originals (2000)

Original track number: 33 tracks (30 game length, 3 longs)
ULTIMATE MOBILE track number: 20 tracks (18 game length, 2 longs)
Removed: 13 songs were removed: Candy Blue～Vocal Best Version, In a Grow, Love Is Strong To The Sky～V.B.-Remaster, Viva!2000, ビーマニ戦隊ポップンファイブ, どうなっちゃったって (and long), 君が好きだよ～守って守ってあげるから, 君が好きだよ～守って守ってあげるから・・・Folky Version, クチビル, 昇りつめるの , Ti voglio bene ancora, and ウルトラハイヒール〜I JUST WANNA TELL YOU.

pop'n music 6 original soundtrack (2001)

Original track number: 42 tracks (22 game length, 11 licenses, 3 longs, 6 BGM tracks)
ULTIMATE MOBILE track number: 21 tracks (15 game length, 0 licenses, 0 longs, 6 BGM tracks)
Removed: 21 tracks removed. In addition to all 11 licenses being removed, the following seven originals, and their three longs, were removed as well: Foundation of our love (and long), Lucifer (and long), 悪の野望はブルース, 走りぬける君へ、Hurry up!, 작은행복, ポップン音頭, and うるとら★ボーイ (and long).

REFLEC BEAT

REFLEC BEAT ORIGINAL SOUNDTRACK (2011)

Original track number: 50 tracks (43 game length, 2 classical remixes, 1 long, 2 instrumentals, 1 BGM track, 1 bonus track)
ULTIMATE MOBILE track number: 48 tracks (42 game length, 1 classical remix, 1 long, 2 instrumentals, 1 BGM track, 1 bonus track)
Removed: Gymnopedie-kors k mix- and Medicine of love have been removed.

REFLEC BEAT limelight ORIGINAL SOUNDTRACK (2012)

Original track number: 53 tracks (49 game length, one classical remix, 2 longs, 1 instrumental)
ULTIMATE MOBILE track number: 51 tracks (48 game length, no classical remix, 2 longs, 1 instrumental)
Removed: 華爛漫 -Flowers- (2nd EDITION) and 威風堂々～チュートリアルより～ have been removed.

REFLEC BEAT limelight ORIGINAL SOUNDTRACK EXTRA (2013)

Original track number: 35 tracks
ULTIMATE MOBILE track number: 33 tracks
Removed: Red Goose and Sweet Rain feat. Karin have been removed.

REFLEC BEAT colette ORIGINAL SOUNDTRACK VOL.1+2 (2013)

Note: The MUSIC PLAYER separates VOl.1 and 2 into two different pages, one for each disc. For consistency with the original OST release, they are grouped together here.
Original track number: 83 tracks (80 game length, 3 longs)
ULTIMATE MOBILE track number: 76 tracks (73 game length, 3 longs)
Removed: Seven songs: Devilz Staircase, Mirage, Screaming Your Faith!!!, Vermilion, コドモライブ, ペリーでぇす！, and 桜.

REFLEC BEAT colette ORIGINAL SOUNDTRACK EXTRA (2014)

Original track number: 50 tracks (45 game length, 2 longs, 3 instrumentals)
ULTIMATE MOBILE track number: 49 tracks (44 game length, 2 longs, 3 instrumentals)
Removed: Russian Snowy Dance has been removed.

REFLEC BEAT groovin'!! ORIGINAL SOUNDTRACK (2014)

Original track number: 53 tracks (46 game length, 2 classical remixes, 3 longs, 2 instrumentals)
ULTIMATE MOBILE track number: 50 tracks (45 game length, 0 classical remixes, 3 longs, 2 instrumentals)
Removed: Snow Eagle, ハンガリー舞曲第5番～Hungarian Dances No.5～, and ラデツキー行進曲～Radetzky March, Op.228～ have been removed.

REFLEC BEAT groovin'!! ORIGINAL SOUNDTRACK (2015)

This consists of disc 1 of the original soundtrack. Discs 2 and 3, listed below, cover the BEMANI MUSIC FOCUS tracks.
Original track number: 22 tracks (20 game length, 2 longs)
ULTIMATE MOBILE track number: 20 tracks (19 game length, 1 longs)
Removed: anqad and its long version have been removed.

REFLEC BEAT groovin'!! Upper ORIGINAL SOUNDTRACK BEMANI MUSIC FOCUS (2015)

Original track number: 40 tracks (37 game length, 3 longs)
ULTIMATE MOBILE track number: 36 tracks (33 game length, 3 longs)
Removed: Funky sonic World, MAD BLAST, Pink Rose, and Presto have been removed.

REFLEC BEAT VOLZZA ORIGINAL SOUNDTRACK (2017)

Originally listed as discs 1 and 2 of the REFLEC BEAT 悠久のリフレシア + REFLEC BEAT VOLZZA ORIGINAL SOUNDTRACK album.
Original track number: 60 tracks
ULTIMATE MOBILE track number: 58 tracks
Removed: FIRE 2 and Viden have been removed.

REFLEC BEAT 悠久のリフレシア ORIGINAL SOUNDTRACK (2017)

Originally listed as discs 3 and 4 of the REFLEC BEAT 悠久のリフレシア + REFLEC BEAT VOLZZA ORIGINAL SOUNDTRACK album.
Original track number: 58 tracks (35 game length, 15 longs, 8 BGM tracks)
ULTIMATE MOBILE track number: 57 tracks (34 game length, 15 longs, 8 BGM tracks)
Removed: 追想ブロカント has been removed.