It's possible there would be some Copyright restrictions too, isn't it?
Anyway, in case you need it sometimes, here are the tools to extract sounds and music (or any data) from MM6 and MM7:
(I notice KingPirux refers to Heroes of M&M, which have indeed great music,especially HofMM3. But actually Arcomage is from MM7 & MM8. ---- Just stating the obvious, I know...)