VIDEO: Sneak Peek - Demi Lovato Guests on Next Episode of GLEE

On the next episode of FOX's Glee titled "Tina in the Sky With Diamonds", as Beatlemania continues at McKinley, it's time for the students to vote for prom queen and king.

When Tina receives a nomination, she takes on a fierce attitude that alienates her biggest supporters. Meanwhile, Rachel adjusts to a new attitude of her own, as she and Santana work at a Broadway diner to make ends meet.

The episode airs Thursday, October 3rd on FOX. Get a sneak peek below!