Hard Rock

As the 1960s saw rock acts like Jimi Hendrix and the Who turn up their amps, bands began to augment their guitar sounds with distortion. Their blues-based structures, with driving rock guitars and pop hooks, were the rudiments of Hard Rock. The basics of Hard Rock haven't changed, but the myriad styles it has spawned -- from Heavy Metal to Power Pop -- have taken those simple elements in hundreds of directions.