If you've ever seen Mean Girls, you may have caught a reference to Ladysmith Black Mambazo, but the South African vocal group is much more than a punchline. They've been around in one form or another since the early '60s, influencing Paul Simon, with whom they collaborated on Graceland, standing as figureheads of the anti-Apartheid movement, and recording a cover of "Knocking on Heaven's Door" with Dolly Parton. Oh, and they were just nominated for a Grammy for 2011's Songs From a Zulu Farm. Puh-retty good bet if you're looking to have your spirits lifted.