Photo Flash: First Look at GLEE's 'Diva Week' Epiosde

Glee is a musical comedy about a group of eager and ambitious students who strive to outshine their singing competition to win Nationals while navigating the cruel halls of McKinley High. Since its debut, Gleehas become a bona fide cultural phenomenon, received prestigious honors including the Golden Globe and Peabody Award and singlehandedly made Glee clubs cool again.

In addition to the regular cast, Glee has featured guest appearances by a wide range of talented performers, including Kate Hudson, Sarah Jessica Parker, Gwyneth Paltrow (who won the 2011 Emmy Award for Outstanding Guest Actress in a Comedy Series), Carol Burnett, Kathy Griffin, Cheyenne Jackson,John Stamos, Britney Spears, Kristin Chenoweth, Idina Menzel, Jonathan Groff, Molly Shannon, Olivia Newton-John and Neil Patrick Harris, who won a 2010 Emmy Award for Outstanding Guest Actor in a Comedy Series for his work on the show.

Photo Credit: Eddie Chen/Adam Rose/FOX

Becca Tobin, Heather Morris, Jenna Ushkowitz, Darren Criss, Alex Newell and Melissa Benoist

Alex Newell

Becca Tobin

Heather Morris

Jenna Ushkowitz, Becca Tobin, Blake Jenner, Melissa Benoist, Jacob Artist and Kevin McHale

Jenna Ushkowitz

Jane Lynch

Heather Morris

Cory Monteith, Jayma Mays