Some are calling 17-year-old hip-hop sensation CHRIS BROWN the new Usher. That's weird because, last I heard, Usher is still around. You can judge for yourself when the man behind radio smashes like "Run It" and "Gimme That" glides through Chastain Park Amphitheatre SEPT. 9. A gaggle of urban music stars like Ne-Yo (right), Lil' Wayne, Juelz Santana and Atlanta's Dem Franchize Boyz join him. $55.75-$65.75. 7 p.m. 4469 Stella Drive. 404-233-2227. www.ticketmaster.com.