How exactly does game/movie soundtrack composing work?

If a game soundtrack is done by one person, and the soundtrack includes electronic music, pianos and violins, how does that one person create all of those tracks? Are they playing all of the individual instruments themselves? Or do they just write the music and have an orchestra play it for them?

Here is an example, is Yoko Shimomura doing everything here or what?

https://www.youtube.com/watch?v=HyT3B6tMQ7Y

I know, composer, just want to be sure though.

it depends on the era, composer, and system. for Kingdom Hearts II, Yoko Shimomura wrote all the songs in MIDI in a DAW (most likely Pro Logic). Takeharu Ishimoto and Hitoshi Ohori are the ones who programmed them into game code.

then take for example, the Dearly Beloved mix for Kingdom Hearts 3D
"Music: Yoko Shimomura
Orchestration & Conducting: Kaoru Wada
Recording & Mixing Engineer: Masahiro Yamada
Recording & Mixing Studio: Avaco Creative Studio Inc.
Recording Coordinator: Emari Mamiya (Genuine)

Violins:
Masatsugu Shinozaki
Tomoshige Yamamoto
Kiyo Kido
Yuriko Mori
Daiki Shimizu
Haruhiko Mimata
Toshiro Murai
Kiyono Aihara
Shohei Yoshida
Kei Shinozaki
Nagisa Sakaki
Ken Okabe
Machi Okabe
Koichi Yokomizo
Violas:
Tomomi Shinozaki
Nao Kaneko
Takashi Yanagisawa
Kaori Minami
Violoncellos:
Masami Horisawa
Takahiro Yuki
Shohei Uwamori
Ou Shinozaki
Contrabasses:
Shigeki Ippon
Yatsuo Tominaga
Harp: Yo Saito
Flute: Hideyo Takakuwa
Oboe: Satoshi Shoji
Clarinet: Tadashi Hoshino
Faggot: Shinkichi Maeda
Horns:
Masato Yoshinaga
Shigeaki Hisanaga
Hirosi Wada
Trumpets:
Shigeo Ohkura
Toshio Tanaka
Eiji Yamamoto
Hisato Yamaguchi
Trombones:
Tomohiko Iida
Miki Murakami
Tuba: Shinpei Tsugita
Piano: Haruki Mino
Percussion:
Midori Takada
Tomoko Kusakari
Yuki Hasegawa"

but as I’ve said, it depends on the game (and even sometimes you will have a mix of synthesized sequence data and streamed audio played by an orchestra in the same game) I can go into more detail if you want.

I can go into more detail if you want.
Please, more examples.

https://www.youtube.com/watch?v=3ZJBb43htII
https://www.youtube.com/watch?v=ecRkTYs46q0
https://www.youtube.com/watch?v=CqZXoRdQsGY

while all 3 games had orchestrated/studio recorded material, these specific 3 were all originally MIDI/done by a single person.

the best way to check, is to look at the album liner notes. it normally credits the people responsible for performing, so if that isn’t there, then it’s most likely done all by the composer in a DAW (again, most likely Pro Logic).

while all 3 games had orchestrated/studio recorded material, these specific 3 were all originally MIDI/done by a single person.

the best way to check, is to look at the album liner notes. it normally credits the people responsible for performing, so if that isn’t there, then it’s most likely done all by the composer in a DAW (again, most likely Pro Logic).
Thanks