Barks.JP has a great interview with Yoshiki focusing on his upcoming release, Yoshiki Classical.
In the case of X JAPAN, you have certain regulations that go along with having drums, piano, and guitar as well as needing to make sure Toshi’s vocals fit with the pieces, but when you as YOSHIKI do classical pieces, do you have any musical rules to follow?
YOSHIKI : Not really. Tentatively, the strings become the main part, that’s about it. For example, when I did the “Golden Globe Theme” for the Golden Globe Awards, while it could be called classical, there were also drums in it, and actually, there was some subtle guitar as well. Almost to the point that you can’t hear it at all… just enough that you can feel it… there’s some subtle bass in there as well.