“I’m Still Here,” Stephen Sondheim’s anthem (from Follies—but you knew that) for indefatigable showbiz troupers, could be the theme song for Showtunes Theater Company, which stages concert performances of unfairly neglected or even forgotten musicals. (Come to think of it, perhaps an even better theme for any theater company might be another number from that show, “Losing My Mind.”) Tonight’s omnibus fund-raising revue will include highlights from STC’s past seasons and previews of this year’s two productions: the rarely staged but cult-worshipped Follies (June 5-6), Sondheim’s dry, wry look at a Ziegfeld-esque showgirls’ reunion, and Call Me Madam (Sept. 25-26), Irving Berlin’s 1950 Ethel Merman vehicle based on the life of Beltway hostess (“with the mostess”) and bon vivant Perle Mesta. GAVIN BORCHERT Sat., Feb. 6, 8 p.m., 2010