As soon as we hear the machine-gun beat of Ian Paice's drums on "Highway Star," it's all over. We have to listen to all of Machine Head from beginning to end—it's just that good. This landmark album is an exultant hard rock classic for a good reason: It’s packed with chugging heavy metal moments, from the psychedelic vocal echo on "Space Truckin'" to the mightiest of all guitar riffs on "Smoke on the Water."