I'm listening to the grasshopper manufacture podcast on
their Facebook page, and on episode two at the 28:35 mark, Yamaoka is asked about his contribution to the
Symphony of the Night soundtrack, where he pretty much just says he did the drum programming. Nothing that hasn't already been revealed before, but it sounds like he did the programming for more than just the song "Crystal Teardrop", which is the only song I've ever read about him working on.