Ludacris will headline at the Marcus Amphitheater on Sunday, July 1 at Summerfest.  The 7 p.m show's lineup also includes Chris Brown, Ciara and T-Pain.  

At the 2007 American Grammy Awards Ludacris took home awards for Best Rap Album, "Release Therapy," and Best Rap Song, "Money Maker."

Since his show at the Harley-Davidson Roadhouse during last year's Summerfest, 17-year-old Chris Brown has been nominated for two Grammys, seen his album go platinum and been named to both AOL's 21 Hottest Young Musical Talents under 21 list as well as People Magazine's Most Beautiful People list. 

Ciara broke onto the scene in 2004 with her number one single, "Goodies." Her second album "Ciara: The Evolution" was released late last year and has spawned three top twenty singles on the Billboard 100 list. T-Pain's single "Buy U a Drank" is currently the number one song on Billboard's Hot R&B/Hip-Hop songs list.