We've had Yeah Yeah Yeahs' disc "Show Your Bones'' on the car CD player most of the summer, and we're liking the idea that this genre slashing blues/punk New York trio doesn't look like it will fade into the ether. Bands with a new twist on things always face that possibility and singer Karen O's caterwauling and sexy/gawky stage persona made that not unimaginable. Karen told one mag the album sounds like what it feels like putting your finger in a light socket. Well, we get the analogy, but it's really more pleasant than that. But they do have that "electrical shocker'' quality the Clash sang about in "Clash City Rockers.'' For their second full-length album, the Yeahs came back with a cool, rocking, infectious effort and you can bet they're gonna kick ass at City Hall Plaza Aug. 10 at 6 p.m. The concert, promoted by WFNX and the Boston Phoenix, is a freebie. Opening up: Another quality act, TV On the Radio.