Choise of music depends much on level,
trance can might not be usefull if there is tons of enemis, that dosen't fit da team =p
Try go on
http://www.modplug.com/
And search for good music in different styles, find the best style you like on level, and search for that kind of style at music.
This should really give you a good music on
all files is most .it and .mod
only 5% of all songs there cannot be used to jazz, rest is useable