Glee celebrates a milestone on Tuesday night.
During the episode "Mash Off," Shelby's new all-female choir will take to the stage and do a lot more than merely mash-up two Adele singles; the group will perform the show's 300th musical number! That's almost as many songs as Sue Sylvester one-liners.
Watch Santana and Mercedes take the lead below, as Shelby looks on proudly and Will looks on in fear:
What else can fans expect on the episode? View the official trailer HERE to find out!