The B.B. KING BLUES FESTIVAL, which hits Atlanta's Chastain Park Amphitheater Thurs., JULY 26, draws together three legendary performers: King, Al Green (pictured) and Etta James. B.B. King may be the most commercially successful blues artist of all time. (Sorry, the Rolling Stones don't count.) A master of the electric guitar and a pioneer who helped modernize blues for urban audiences, King has scored hits since the early '50s, all the way to 2000's Riding with the King album with Eric Clapton. Neither Al Green nor Etta James needs introduction, either. Green is a timeless interpreter of soul classics and countless female artists from Amy Winehouse to Beth Ditto of the Gossip cite husky, forthright R&B singer James as an influence. For more on Green, see Vibes. $38.50-$85.50. 7 p.m. Stella Drive and Pool Road. 404-233-2227. www.chastainseries.com.