When it comes to divas, Gladys Knight is the best thing that ever happened to Atlanta. The seven-time Grammy winner, Rock and Roll and Georgia Music halls of fame inductee, and chicken-and-waffle entrepreneur gave her heart and soul to rhythm and blues over the past five decades. And while she's the subject of the National Black Arts Festival's LEGENDS CELEBRATION: AN EVENING WITH GLADYS KNIGHT Fri., JULY 18, the former leader of the Pips shows no signs of slowing down. Just check out her warm, rich duet with Johnny Mathis on the title track of his 2008 release, A Night to Remember. She's also appeared at the "Divas With Heart" fundraiser in New York and on "American Idol" (but not as a contestant) this year. Why? That's what friends are for. $20-$76. 8 p.m. Atlanta Civic Center, 395 Piedmont Ave. 404-658-7159. www.ticketmaster.com.