Exploring Tom Petty's lesser-known output makes it clear that he's incapable of penning a bad tune. A gem of mid-'80s heartland rock, “Rebels” showcases his Dylan-esque cry at its most passionate. “Century City” is an anti-music industry scorcher, one whose sneer puts him in league with the punks. Unplugged and countrified, the gently picked “Angel Dream (No. 2)” is just as potent.