In 2001, he made his solo R&B debut album, The Return of Mongo Slade, for Atlantic Records. Because of contractual changes, it was never released by the label. Hidden Beach Recordings, an independent label, acquired the masters from Atlantic and released the album as Back to Then in July 2002. The album included work from the production team of Jill Scott, and she made an appearance on the track "Hold On." The single "This Is My World" was featured in the 2001 comedy film Shallow Hal. In regards to the album, "That was just a minute in my life," he later told The Arizona Republic about the record. "I was listening to a lot of Notorious B.I.G. and Lauryn Hill at that time, and I wanted to make a neo soul record." He also said in the article that he doesn't anticipate recording an R&B-styled disc again. "Country music is my day job now. I'll probably do this till it's all over, but that album was a lot of fun." Rucker appeared on a pop-star edition of the quiz show Who Wants to Be a Millionaire? in July 2001. He also portrayed a singing cowboy in a television commercial for the fast-food company Burger King, promoting its TenderCrisp Bacon Cheddar Ranch sandwich in 2005. In the commercial, he sang a jingle set to the tune of "Big Rock Candy Mountain."In 2006 Rucker lent his voice to the track "God's Reasons" written by Dean Dinning and Joel A. Miller for the film The Still Life.