Rights to Music

[CoyCoyCoy]

Apologies if this has been answered somewhere else! I'm interested in doing a skit that's a Death Note parody of Gay or European (Gay or Simply Kira). My group will be doing our own voice acting of the parody song to lip-sync to, but we'd like to use the backing track from the musical. I saw lots of groups using music that must be copyrighted in the skits, but I'm not sure how you get licenses to this stuff - or if Anime Boston takes care of that with a blanket license or the like? Could anyone advise me on this?

Thanks for your time!