UPDATED!

Idina Menzel guest-starred as a mentor on Sunday’s episode of American Idol! You can watch a behind the scenes clip of Idina meeting the contestants above and the entire episode on ABC.com.

Idina will also appear on Undercover Boss: Celebrity Edition on May 18 at 8 PM on CBS! Idina will try to remain incognito when she’s asked to sing “Let it Go” to a group of children. Also, while undercover as a receptionist who wants to break into the musical theater business, Idina will try to disguise her voice as she sings alongside a wedding singer at a wedding reception, and she might chicken out when suiting up for a singing telegram job. See photos in the gallery!

Here’s a preview: