This must be where I proclaim my love for Kajiura Yuki and her awesome Xenosaga III & II OSTs.
1. Xenosaga Episode III: Also sprach Zarathustra - Kajiura Yuki
Testament. Godly song. The whole song is great, but 1:48 onwards is just on a whole other level.
Promised Pain. Final boss music. It is awesome in its own right but as far as boss theme goes, I thought
Godsibb sounded even more epic. I'm not saying promised pain was a bad song. On the contrary, I think it's better than most boss themes. The problem is that Godsibb exists. Nothing like a Kajiura boss theme to make you feel "OH SHIT. It just doesn't feel like I can win" 勝てる気がしない. That's just the music though.
2. Akai Ito - MANYO
MANYO is a composer from Japan who mostly composes for visual novels. He has worked on pretty much all of Innocent Grey's VNs. His recent work include Flowers, a VN series from Innocent Grey, and D4: Dark Dreams Don't Die, for which he was responsible for the majority of.
For a VN, the music really sets the mood and atmosphere and this OST does an
excellent job at doing that.
Since there is no official English title, I've provided the translated title in parenthesis.
古唄 (Ancient Song) does a great job at bringing in the traditional Japanese feel of the VN, which is heavily steeped in traditional Japanese folklore.
A WARNING that the image used on the next two youtube videos can be kind of NSFW. Unfortunately they were the only ones I could find.
時の雫 (Drops of Time). A relaxing track. Sometimes used during day to day scenes, but mostly used after a tense moment has passed and they're glad to be alive.
夢の苧環 (Yume no Odamaki) Menu music. It brings you straight into Akai Ito's world. There's a very dreamy feel to it, fitting for the title which I have no idea how to translate. Sorry.
いつかのひかり (The Light of Someday) A piano piece that still tugs at my heart strings. It's pretty much the theme of my favourite character, Yumei. Suits a lot of the tender moments shared by her and the MC, Kei. It also has
a vocal version, one of two sung by Shimotsuki Haruka, both of which were written after having been chosen from the OST by popular vote,
four years after the game was first released.
去り逝く者、残される者 (Those Who Pass Away, and Those Who Are Left Behind) is an arrangement of the opening song,
Mawaru Sekai de (Vo: Shimotsuki Haruka/Riya), which was also composed by MANYO. As the title would suggest, this is a song played during bad endings, endings this VN is full of.
泡沫 (Bubbles) For everything will eventually disappear, as though they were as transient as bubbles. The overall winner of the popularity vote for a vocal version. I'm actually quite surprised that the vocal version wasn't written first.
This is the original song of the same name. Despite what that second link says, this song, especially with its lyrics, is clearly Sakuya's theme song. Saying any more will go into spoiler territory.
3. Aoi Shiro - MANYO
A sequel to Akai Ito (lit, the red string of fate, but there are many word plays on the title itself and is thus written using Katakana instead of Kanji), and set in the same world with different characters. Just as Akai Ito took up the theme and colour of red, and was mainly set in a forest/mountain setting, Aoi Shiro (lit. blue castle) takes on the colour of blue, and features the ocean heavily; something which I think, can also be felt in the OST. I curse the bankruptcy of their parent company, SUCCESS, which has robbed us of any chance for any more sequels.
水の囁き (Water Murmurs). The menu music. I could probably sit on the menu forever. Like Akai Ito's menu music, there's a very atmospheric feel to it that helps immerse you in the world the VN seeks to create. I really like his use of strings here.
瑠璃の宮処 (Palace of Lapis Lazuli)
悠久の彼方から (From the Other Side of Eternity) is basically Aoi Shiro's version of Ancient Song. One of the first songs played in the game, where the teacher speaks about the legend of the Oni on the island across from where they are having their summer camp.
龍捷虎搏 (Swiftness of a Dragon, Spring of a Tiger). One of the battle themes. Has a bit more fight to it than the ones in Akai Ito since Kei was a defenseless school girl who mostly just ran away; sometimes ironically to her death. Comparatively, Syouko, the MC in Aoi Shiro, knows Kendo ...although she still isn't much of a match against the kind of enemies that show up in this VN. Still, it's a lot less Horror! Run! than the first OST.
闇の彼方に (Beyond the Darkness). Opening song sung by Rita/Shimotsuki Haruka. Features the same layering/harmonising of voices/lyrics as Akai Ito's OP. The ED,
Minamo Made is a ballad, and is just as nice. As with Akai Ito, the singers lead one song each.
4. Xenosaga Episode II: Jenseits von Gut und Böse - Kajiura Yuki
I'm actually quite torn about putting Xenosaga II here. As much as Kajiura's tracks were awesome, those that weren't hers... not so much. Still, I'm just so in love with these.
Assault, like quite a number of other tracks, is an arrangement of the theme song "sweet song", which was also composed and written by Kajiura Yuki herself. This arrangement, however, is completely different from the original song in terms of feel. It's dark. It's ominous. It's everything I love about Kajiura.
Communication Breakdown was criminally underused in the game. It did, however, get a nice PV that made everything seem so exciting.
The Image Theme of Xenosaga II. I've linked the live performance that was re-arranged by Kajiura herself, performed by FictionJunction, with Kajiura on the keyboard. How glorious is that build up. It practically melted my brain when I listened to it live.
5. Shadow of the Colossus - Otani Ko
Prologue - To the Ancient Land,
A Despair-Filled Farewell - Battle with the Colossus,
The Farthest Land
I decided to go with only one battle theme because although they made the fights great, the other two set the atmosphere and feel for the entire game.
6. Kingdom Hearts II - Shimomura Yoko, Utada HIkaru
Fate of the Unknown,
Passion,
The Other Promise
7. Kingdom Hearts - Shimomura Yoko
Dearly Beloved,
Destati
Honorable mention:
Kingdom Hearts Series - Shimomura Yoko
From Shimomura's best of album, Drammatica,
The 13th Anthology
An orchestral re-arrangement of several songs from across the Kingdom Hearts Series. Since it is not a track available on the original soundtracks, but only in her personal album, and since it spans multiple games, I included it here. Notable songs used in this track include
Another Side,
Organization XIII,
The 13th Struggle,
The 13th Reflection,
Graceful Assassin,
The 13th Dilemma and
Lord of the Castle.
I'd be very disappointed if at least Xenosaga 3 was nowhere near your top.
No worries there. *thumbs up* Where else could it ever be.
Apologies for not being able to resist adding a few more songs to Akai Ito and Aoi Shiro. They're my favourite VNs of all time after all. Truth be told, there are quite a few more that I would have loved to add but I shall refrain from doing so.
By the way, Akai Ito was released as a PS2 archive game in the Japan and Asian PS Store for the PS3!