Watch! Gwyneth Goes 'Glee'

Actress and singer Gwyneth Paltrow is making her "Glee" debut Monday as substitute teacher Holly Holiday -- and she's set to perform a medley of "Singin' in the Rain" and Rihanna's "Umbrella."

Take a sneak peek at next week's episode, set to air Monday at 8:00 PM PST on FOX.