Sources seem to vary on which video game was the first to use an actual orchestra to perform its soundtrack. Some sources say that it was Heart of Darkness.
Heart of Darkness marked another change in game music history, being the first game ever to contain original music scored by an actual orchestra.
The above article and other sources claim that Heart of Darkness, released in 1998, was the first video game to have music performed by an actual orchestra. However, this is apparently untrue since Total Annihilation, released in 1997, also had a soundtrack performed by an orchestra (link to YouTube video of the Total Annihilation soundtrack playlist).
The game has an original orchestral soundtrack composed by Jeremy Soule and performed by the 95-piece Northwest Sinfonia orchestra.
The game was notable for being one of the first console games to use a fully orchestrated soundtrack.
Composer: Dark-Wizard Sound Team
Conductor & Arranger: Toru Akasaka
Performer: Tokyo Sonic Orchestra
I’m not sure if the above Wikipedia article implies that the soundtrack of Dark Wizard was performed by an actual orchestra*, but the VGMdb credits suggest that it was, as it lists the "Tokyo Sonic Orchestra" as the performing group. The soundtrack sounds electronic to me, but this may be due to audio compression or because I am only listening to the electronic parts of the soundtrack, and there are other parts performed by an actual orchestra.
* To address a comment that was made regarding the definition of "orchestrate", according to Oxford Languages via Google, "orchestrate" means “arrange or score (music) for orchestral performance” (emphasis mine). According to Cambridge Dictionary, it means “to arrange or write a piece of music so that it can be played by an orchestra” (emphasis mine).
Note that I’m only interested in the earliest example of a game soundtrack that was performed by an actual orchestra, not synthesized or electronic music.
What was the first video game to have a soundtrack performed by an actual orchestra?
The name of the orchestra that performed the soundtrack would also be helpful.