Ever wanted to hear a bluegrass version of "Owner of a Lonely Heart"? (Come to think of it, we never wanted to hear the prog-rock electro-pop version.) There's only one place tonight in Nashville where you'll hear it: at 12th & Porter, where The Cleverly Trio plays a free showcase at 6 p.m. The native Arkansas quintet (?) of bluegrass/Branson cats are said to be developing a TV pilot with Prototype Media, and this is their first Nashville appearance. Requests for side one of Tales from Topographic Oceans are encouraged.