On September 14, 2004, Nelly released two albums, "Sweat" and "Suit". "Suit", an R&B-oriented album, debuted at number one on the "Billboard" albums chart, and "Sweat", a rap-oriented album, debuted at number two. From "Suit", the slow ballad "Over and Over", an unlikely duet with country music star Tim McGraw, became a crossover hit. On the 2004 NBC television concert special "Tim McGraw: Here and Now", McGraw and Nelly performed the song. A feud with another St. Louis-based rapper, Chingy, came up near the end of the year. "Tsunami Aid: A Concert for Hope", a 2004 Indian Ocean earthquake benefit concert special produced by NBC, featured Nelly. In the winter of 2005 came "Sweatsuit", a compilation of tracks from "Sweat" and "Suit" with three new tracks. "Grillz", produced by Jermaine Dupri, was a number-one hit. To date both albums have sold over 5 million units in the United States.