"American Idol" will return next month with a two-night, four-hour premiere featuring auditions in Boston and Atlanta, the Fox network says.

The Boston auditions will air Jan. 12 and the Atlanta auditions will air Jan. 13. Fox says auditions will also be held in Chicago; Orlando, Fla.; Dallas; Los Angeles and Denver.

This year's big change: Ellen DeGeneres is replacing Paula Abdul as judge. DeGeneres will join the show in February, after the tryout rounds, Fox says.

Guest judges at the auditions will include Victoria Beckham, Mary J. Blige, Kristin Chenoweth, Neil Patrick Harris, Joe Jonas, Avril Lavigne, Katy Perry and Shania Twain.

Abdul announced she was quitting amid a contract dispute earlier this year.

Twelve male and 12 female semifinalists will be announced Feb. 17, with voting to begin Feb. 23. Last season, "American Idol" brought 36 men and women to Hollywood to compete, compared with two dozen in previous seasons. The network said in an e-mail that no one was available Thursday to comment on that change.