Can you hear guitars clashing, synthesizes rattling? That’s the clamor of bands getting ready for the annual battle of the bands that EMP Museum calls Sound Off! Twenty-one semifinalists have been selected, from Seattle, Portland, Tacoma, Bellingham and other towns in the region, playing everything from electro-pop to hip-hop.

The contest has helped launch the careers of lots of up-and-coming bands, including The Lonely Forest, Dyme Def and Land of Pines.

Bands competing in round one are Dave B (Renton), Mister Mista (Seattle), The Fame Riot (Tacoma) and Shogun Barbie (Tacoma).

Round one gets under way at 8 p.m. Saturday at EMP, 325 Fifth Ave. N., Seattle; $8-$12 (206-770-2700 or www.empmuseum.org).

Seattle Times staff