One could easily make a case for or against the roll of music in yoga practice. On the one hand music/sound has played an intimate roll in the history of yoga (particularly in the nada and bhakti yoga traditions). On the other hand the power of sound can unduly influence the environment and mind of the practitioner, distracting one from the immediate perceivable reality.
Without going into too many details, I have been privy to both ends of the spectrum; having experienced the acute and transformational power of sound, largely from classically based Indian genres, to having my nadies and vritties accosted by the likes of Michael Jackson, Def Leopard, and Huey Lewis. Rock On.