Judas Priest, Whitesnake

Judas Priest started its metal odyssey in the early '70s, when bands from the industrial-wasteland towns of northern England were just starting to set fire to traditional blues riffs, and its constant output and evolving sound helped it to transcend fickle trends over the years.

Whitesnake's music, however, exists in a very definite space and time. Its older fans simply want to rock out to "In the Still of the Night" and "Here I Go Again" and reflect on the glory days, while the younger crowd loves to revel in secondhand nostalgia.

But each band's stellar musicianship will overcome the groups' differences—whether it's Rob Halford's spine-tingling falsetto, K.K. Downing's lightning-fast lead-lines, David Coverdale's smoky rasp or Tommy Aldridge's Bonham-esque drumming. Either way, metalheads of all stripes will wake up on Friday morning with sore throats and crooks in their necks.