Barbara Martin at Potomac Overlook Barbara Martin is a renaissance woman in music genres prone to stereotypes and pigeon-holes. She writes award-winning songs, plays guitar and collaborates with other artists to produce engaging live shows and music education programs. Saturday, July 6, 7-9 p.m. at Potomac Overlook Regional Park, 2845 N. Marcey Road. Call 703-528-5406 or visit www.nvrpa.org/potomacoverlook.