Thanks to some leads from a few dedicated wizard rock fans, the Wizrocklopedia is happy to introduce you to:

Crabbe & Goyle (Rock/Death Metal/Grunge), who currently have two songs.

Nearly Headless Nick (Indie/Progressive/Experimental) with the song “Panic at Hogwarts.”

Animagus (Folk Rock/Indie/Americana) with “We Don’t Get Along.”

And Bob-O (Other), who does indeed have at least three songs about the Harry Potter series, despite the somewhat “un-wizardly” band name!