Minstrel's Bargain by Richard Ayre

Minstrel's Bargain is a horror novel set in the late 1980's. It is about a new band, hot on the scene. Music reporter Phil Sturgess thinks they are the best band he's ever seen, but it soon becomes apparent to him that the band is something more than they appear. The leader of the band is, in fact, a demon called Minstrel whose music steals the souls of those who listen to it and he makes them carry out violent murders and suicides. Sturgess has to team up with a tramp who has been following him, and at the end, Sturgess must face Minstrel alone. He tracks him down to hell to finish him off.