The season three premiere of Glee will be titled "The Purple Piano Project." Make of that what you will.

Airing on September 20, the episode will focus on Will handing out a task to his charges, in order to help them cope with the loss at Nationals, and also on Sue's aspiring political career.

What was it like for the cast to return to the set? What musical numbers can we look forward to? The following video takes us behind the scenes of the hit Fox show, as various stars speak on what's ahead.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.