Paul McCartney revealed that nothing gets his blood pumping more that the beloved '50s classics from his childhood. During a chat with Britain's' Radio 4, "Macca" explained that he listens to powerful early rock when working out: "I happened to have a great old jukebox that Capitol records gave to each of the Beatles years ago, and it happens to be in the gym area. I listen to all these old records, 'Rock And Roll Music' by Chuck Berry, 'Somethin' Else' by Eddie Cochran, 'Tutti Frutti' by Little Richard -- it's endless. I really love it! I've been really enjoying that a lot recently."

A while back, McCartney pointed out that with Liverpool being a seaport city, kids were fed a steady stream of popular music they never would've heard had they had been stuck out in the sticks: "Y'know, it's that thing where kids know about something and the grown-ups don't know about. And that gives it a totally magic air. And you were getting friends who had, like, blues records, and stuff, in Liverpool being a seaport, a lot. I think you'd get a lot of imports, and C&W, and blues -- there was a lot of that knocking around. Chuck Berry and Ray Charles 'What I'd Say,' and stuff like that."

AUDIO: PAUL MCCARTNEY ON HEARING EARLY ROCK IN LIVERPOOL