While not celebrated as pioneers of heavy metal as often as contemporaries like Black Sabbath and Led Zeppelin, Deep Purple were as integral a band as any in the evolution of high-octane rock. Essential tracks the group from its early days doing soul-fried heavy blues-rock numbers like "Hush" or their rowdy take on Neil Diamond's hit "Kentucky Woman" into their mid-'70s arena rock apex. Ritchie Blackmore's instantly recognizable riff on "Smoke on the Water" has launched the guitar careers of countless starry-eyed metalheads, and a wealth of other FM radio classics like "Highway Star," "Woman from Tokyo," and "Space Truckin'" is a reminder of just how hard working Deep Purple were. They were also an act that helped usher in the popularity of the double live album with 1972's platinum-selling Made in Japan. Included from that set are "Black Night" and the extended epic jamming of "Child in Time."