How would you know? I'd say two things. One is that you weren't there at the time, and two is that the resultant sound is the end product of a creative process. I've listened to the songs, but haven't given this album any thought for... well, since way back then. Correct me if I'm wrong, but I think that quite a lot of it is multitracked and mixed with collaboration from artists around the world. Whilst that's hardly synthesiser, it is also a long way away from a live recording of, say, a classical solo violin. With that, even though you still wouldn't have been there at the time, it might be just a shade more valid to compare it to your scale of what a violin should sound like.