Moterhead's overwhelmingly loud and fast style of heavy metal was one of the most groundbreaking styles the genre had to offer in the late '70s. Though the group's leader, Lemmy Kilminster, had his roots in the hard-rocking space rock band Hawkwind, Motorhead didn't bother with his old group's progressive tendencies, choosing to amplify the heavy biker rock elements of Hawkwind with the speed of punk rock. Motorhead wasn't punk rock -- they formed before the Sex Pistols and they loved the hell-for-leather imagery of bikers too much to conform with the safety-pinned, ripped T-shirts of punk -- but they were the first metal band to harness that energy and, in the process, they created speed metal and thrash metal. Unlike many of their contemporaries, Motorhead continued performing into the next century. Although the band changed its lineup many, many times -- Lemmy was its only consistent member -- they never changed their raging sound.