Well, here is the kicker. It is a band from the sixties. Not many experimental acts survived that era. But then again, many bands at that time were pushing the boundaries of popular music. Check put their two first albums:
Velvet Underground & Nico
White light/White Heat
Oh, and the lyrics are really awesome, considering the time. They are mostly realistic accounts of drug use and the drug culture in new york at the time. And a great insight into Andy Warhol´s factory society.