N.Y.C. duo Camp Lo headlines this week's Stand Up, Be Counted hip-hop concert, which doubles as a voter-registration drive. The show also commemorates Martin Luther King Day. No surprise, since Camp Lo has always ranked among hip-hop's most socially aware groups. Back in the day, the guys palled around with members of pioneering backpack rappers De La Soul and Digable Planets. And their blend of old-school beats and surrealist rhymes made them favorites of the alt-rap community. Recently, Camp Lo hooked up with the hipster-approved Definitive Jux label. Local rappers TUT, Ace Boogie, and Poetic Republic will also perform at the show. Plus, the Illstyle Rockers b-boy dance crew will bust some fly moves.