Plenty of rock bands kicked ass in the '70s, but how many of 'em did it with street-tough poetry as part of the equation? Thin Lizzy's imagistic hard rock was propelled by bassist Phil Lynott's tough-sounding voice as well as a snaking, twin-lead guitar sound that would prove hugely influential. The group really hit their peak on this 1976 album. Jailbreak contains the band's only US hit, "The Boys Are Back In Town," but all the songs on it swagger and bounce without the cheesy self-mythologizing most of their peers fell prey to. This is nothing less than a literate hard-rock record, as essential to your musical understanding of the '70s as anything by T. Rex, Skynyrd, AC/DC, or even Springsteen.