Superstar Duets

Since winning American Idol in 2002, Kelly has carved out a successful career—including two Grammy wins. Her 2004 album, Breakaway, sold 6 million records in the United States and 11 million worldwide, according to her website. And her latest album, My December, debuted at number two on the Billboard charts in summer 2007.

Although Reba says she was worried about taking up her friends' time when they were recording the Duets album, Kelly doesn't think it was a burden at all! "It's not really 'taking up your time.' It's cool," she says. "It's not like, 'Oh, I have to go sing with Reba,' " she jokes.