Is there any Assassin's Creed sheet music for sale out there? I am a Viola player, but I am able to use Violin music. I am asking about Official Sheet music for sale, not any of the illegal copies or anything like that.
Well, here's something that may help you:
That's the official site of the composer Jesper Kyd who did the music in AC2. Try to contact with him and he might help you further...
I've seen transcribed sheet music/tabliture on various websites. Depends what instrument you're looking for I guess.
On ultimate-guitar if you can find a GP5-GP6 file it'll usually include all instruments with tabs and sheet music formats.