The episode, which airs at 8 PM ET on Fox, features ten fan-chosen "Glee" songs from previous episodes that will be re-mixed and performed by the current members of New Directions. "Defying Gravity" was previously performed on the show's first season.
Reuniting on the March 18 episode of "Glee" are Amber Riley (Mercedes), Mark Salling (Puck), Dianna Agron (Quinn), Harry Shum, Jr. (Mike) and Heather Morris (Brittany).
"Glee" is produced by Ryan Murphy Television in association with 20th Century Fox Television. Murphy, Brad Falchuk, Ian Brennan and Dante Di Loreto serve as executive producers.
Click here for photos from the episode.
For more on the series, visit Fox.com/Glee. Listen to "Defying Gravity":