Mash-Up is the GLEE episode that will air next Wednesday on Fox 9PM/8PM Central. According to Yahoo, it will be another episode chock-full-o-songs, from Neil Diamonds Sweet Caroline to Siquo's Thong Song. Everyones favorite bad boy, Puck, will be singing Neil! But the featured song in the preview is teacher Will Schuester singing Young MC's Busta Move.
GLEE: “Bust a Move” @ Yahoo! Video
And here is a little hint to the storyline.