the Ordinale Scale OST page on vgmdb has full credits
http://vgmdb.net/album/64049
DISC 1 - Original Soundtrack
All Songs written by Yuki Kajiura
Producer: Yasunori Mori (SPACE CRAFT MUSIC PUBLISHERS)
Recording & Mixing Engineer: Takashi Koiwa (SIGN SOUND)
Recording Engineer: Kouzou Miyamoto (Studio A-TONE)
Recording Studio: SOUND CITY / Studio SoundValley / SIGN SOUND STUDIO
Musicians Co-ordination: Kazuo Sudo (HOT WAVE)
Scopre Support: Hiromitsu Ishikawa
Mastering Engineer: Machiko Suzue (Sony Music Studios Tokyo)
Mastering Studio: Sony Music Studios Tokyo
MUSICIANS
ALL Keyboards & Programming: Yuki Kajiura
Vocal & Chorus: Remi [M6,45]
Chorus: Yuriko Kaida, Tokyo Philharmonic Chorus [M45]
Flute: Rie Akagi [M22], Hideyo Takakuwa [M20]
Guitar: Koichi Korenaga [M6,9,14,27,35,37,41,43,45,47,48]
Acoustic Guitar: Koichiro Tashiro [M20,33,39,42]
Drums: Kyoichi Sato [M48]
Bass: Tomoharu "jr." Takahashi [M14]
Cello: Masami Horisawa [M2,12,23,38]
Violin: Kiyo Kido [M12]
Strings: Kiyo Kido Strings [M3,8,9,13,14,21,27,32,34,37,40,41,42,43,45,46,47,48,50]
DISC 2 - Insert Songs
M1
Lyrics: hotaru
Music, Arrangement: yashikin
M2,3,5
Lyrics, Music, Arrangement: Yuki Kajiura
M4
Lyrics: hotaru
Music, Arrangement: eba
Producer: Yasunori Mori (SPACE CRAFT MUSIC PUBLISHERS) [M2,3,5]
Recording & Mixing Engineer: GENDAM [M1,4], Takashi Koiwa (SIGN SOUND) [M2,3,5]
Recording Engineer: 曽野恭平 (DUTCH MAMA STUDIO), Kouzou Miyamoto (Studio A-TONE) [M2,3,5]
Recording Studio: Victor Studio / STUDIO Somewhere / Studio Cubic [M1,4], SOUND CITY / Studio SoundValley / SIGN SOUND STUDIO [M2,3,5]
Musicians Co-ordination: Kazuo Sudo (HOT WAVE) [M2,3,5]
Scopre Support: Hiromitsu Ishikawa [M2,3,5]
Mastering Engineer: Machiko Suzue (Sony Music Studios Tokyo)
Mastering Studio: Sony Music Studios Tokyo
MUSICIANS
Keyboards & Programming: yashikin [M1], Yuki Kajiura [M2,3,5], eba [M4]
Vocal: Yuna (CV: Sayaka Kanda)
Chorus: Remi, Yuriko Kaida [M2,3]
Flute: Rie Akagi [M5]
Guitar: yashikin [M1], Koichi Korenaga [M2,3], eba [M4]
Guitar Tech: Kazutaka Minemori (MASTERTONE) [M1,4]
Drums: Yuu "masshoi" Yamauchi [M1,4], Kyoichi Sato [M2,3]
Bass: Yuichi Takama [M1,4], Tomoharu "jr." Takahashi [M2,3]
Strings: Kiyo Kido Strings [M2,3,5]
More strings miss Kajiura they arent enough!
[EDIT]
http://kiasukid.blogspot.gr/2017/03...dinal-scale-soundtrack-unboxing-comments.html
https://1.bp.blogspot.com/-5UMJ4sY4...iura+Yuki+SAO+Ordinal+Scale+OST+unbox+018.JPG