SAN FRANCISCO--At the Elbo Room in the Mission District last night, two emerging groups and more than 200 people exposed themselves to one another.

At MP3.com's Get Exposed concert, Cali hip-hop troupe Native Guns weaved political prose and party rap into the kind of classic hip-hop that feeds the mind and forces the a** to follow, while Brooklyn-based garage pop band the Shapes filled the room with a heap of deliriously infectious garage pop hooks.

Native Guns won MP3.com's Get Exposed contest, where artists uploaded their music to MP3.com and users chose the top of the class. They landed free Zune portable media players and a headlining slot, with second-place the Shapes flying out from NYC to round out the bill.

The Shapes got the night started with one of their best songs, the ultra-catchy "Monster," which uses a bouncy guitar riff and a synth line that sneaks up on you to great effect. Singers Mark Allen and Tonia Samman shared vocal duties and harmonized well throughout the set.

Allen and Samman were at their best on "Dreaming of an M16," a track that would have fit perfectly in the annals of CBGB's before it closed. Behind a throbbing bass line and wailing guitars, the pair traded flirtatious banter, mixing grit with glee and sending the crowd into a pop-rock tizzy.

Native Guns--emcees Kiwi and Bambu and DJ Phatrick--were up next.

If these cats are somehow able to break through to a wider audience, hip-hop will be in a better place. Over the kind of beats that add a West Coast swagger to the minimal, jazzy vibe of their Native Tongues sonic forefathers, Kiwi and Bambu write rhymes that make political rap go down easy on the palate.

On "Champion," the duo boasted of their lyrical prowess, work ethic, and stance against social injustice. Kiwi's verse on the track might as well serve as the group's MO: "This Native Guns shot is like a poisonous arrow / Let everything hang when we come out the barrel / Keep it grounded pound the pavement / Hitting the boulevard with my brother adjacent / We sick of all these actors and all the drama they spit / We taking it back to when rappers actually said s***."

The two rappers grew up as self-confessed gangsters in Los Angeles but have transformed themselves into dynamic emcees that make conscious rap sound exciting again. Native Guns even threw in a medley of old-school party favorites like Dr. Dre's "Nuttin But a G Thang" and Ice T's "6 'N the Mornin," and adding their own twist to Notorious B.I.G.'s "Juicy."

It was a pretty jubilant night all around, built around the sounds of two groups doing big things in 2007.