Depends on the track.
Some audios are converted from public domain midis, and i have no idea who is the authour.
Other audios are created by friends of mine.
guitared musics created by ahavasi ( no online portfolio avail. ), dnb-like tracks created by v150r (
http://v150r.newgrounds.com/ )
from them i get a ,,to add my maker and to games created with my maker'' license.
you can contact with v150r, i think he will give permission for his tracks
btw i am curious, what project are you planning to create with rpg musics? an rpg probably? :P
(poor nouveau topic)