How would Maddie & Tae fare if they auditioned for 'American Idol'? The 'Fly' singers found out during a recent radio interview. Keith Urban was on the phone, and he didn't know he was being set up.

Maddie & Tae were in studio doing an interview with US 99.5 in Chicago when Urban called. They pretended to be a local duo called the Nuf-Nuffs, and hosts Lisa Dent and Ramblin' Ray asked Urban if he'd let them through to Hollywood.

After singing a version of the Judds' 'Have Mercy,' the newcomers paused for feedback. "Woo! That is some tight harmonies," Urban says near the end of the clip. But would he send them through, and did he know he was being set up? Watch the full video to find out.

After the fun, Urban talks about his new single 'Raise 'Em Up,' a duet with Eric Church.

Keith Urban and Other Stars' Yearbook Photos