Carrie Underwood‘s cover of Heart’s “Alone” on American Idol is now one of the most memorable performances from her winning run on the show back in 2005. But at the time she sang it, Underwood admits she was nervous.

Carrie Underwood’s return as an American Idol judge was considered a significant move for the singing competition show, but may not continue beyond one season. Carrie, the winner of Season 4, replaced Katy Perry upon her departure after a multiple-season run.

Carrie Underwood shared a look at what happened during a commercial break on American Idol on Sunday evening (April 20). Underwood led an a cappella sing-along of “Before He Cheats” with the Idol audience.