The New Wave of British Heavy Metal (NWOBHM) occurred in the late 1970s after the fall of the original British heavy metal bands like Led Zeppelin and Black Sabbath. The progressive sounds of metal were sped up and turned into blistering power chords.
... 1965 the band made the stylistic switch from folk music to rock music, with Jerry Garcia, Ron Pigpen McKernan and Bob Weir[?] from the Jug Champions joined ...