Adele's 2009 debut album, 19, was a Grammy-winning smash hit that revealed the British singer/songwriter's knack for bittersweet soul and folk-infused love songs that brought to mind an infectious mix of dusty springfield and terry callier. The album earned her a ton of fans, and interest was high for the inevitable follow-up. In many ways, her sophomore album, the similarly age-appropriate-titled 21, is a continuation of the sounds and themes adele was working with on 19. She is still the bluesy pop diva with a singer/songwriter's soul and seemingly bottomless capacity for heartbreak. The best thing the album does is to showcase Adele's titanic vocal ability, which more than a few times on 21 is simply spine-tingling. While the track certainly owes a heavy debt to the punk-blues of beth ditto and the gossip, it is also ridiculously sexy and one of the best singles of any decade.