Tonight’s Positive Force concert will both benefit good causes and offer a good survey of current post-harDCore styles. The money goes to Community Family Life Services (which works with the homeless) and Amnesty International; the music comes from urgent blues-punkers Monorchid, edgy minimalists the Warmers, stripped-down prog-rockers Trans Am, and Gift to the Greedy. At 7 p.m. at the home of Community Family Life Services, Trinity Lutheran Church, 4th & E Sts. NW. $5. (703) 276-9768. (Mark Jenkins)