11:00 a.m.-6:00 p.m. Harbor Park, Rockland. The acclaimed Blues Festival features national touring artists. Saturday night, Rockland’s Main Street is closed to traffic for a Blues Club Crawl to more than 15 clubs featuring blues bands. Advance tickets (one day $25, weekend $45): 207-596-6055; 207-593-1189; www.northatlanticbluesfestival.com