It's passive as hell, but I think it could work.
Try to get a feel for what music he likes.
Start talking music with him and mention a few bands he might like that you're into-- like you're doing him a favor and just want him to experience this great stuff.
Burn him a few CDs of music you like that he may also like.
Have him listen to it.
If he hates it, go back to step 1.
Repeat until he's listening to the music you can stand and he has a new appreciation for.