In my opinion, good music for practicing magic depends on one's preferences and tastes.
I enjoy classical music, such as Mozart and Beethoven, when I'm practicing. Moreover, anything from
Dana Hocking is also preferable. On the other hand, a friend of mine prefers music from Led Zeppelin and Linkin Park, when practicing magic -- both of which I listen to on a casual basis, but not for magic.
Sometimes, no music is the best music.
Cheers,
JTM