AUDIO: Preview Songs from GLEE's Britney Spears Episode

New Directions performs Britney Spears' most iconic and memorable songs, including "Toxic," "...Baby One More Time" and "Me Against The Music," and the pop princess herself makes a special cameo appearance on an all-new, sure-to-be-fan-favorite episode of GLEE airing Tuesday, Sept. 28 (8:00-9:00 PM ET/PT) on FOX.

In the "Britney/Brittany" episode, MR. SCHUESTER (Matthew Morrison) insists that the glee club perform adult contemporary music at the school assembly, but the kids have other plans. As New Directions mounts its campaign to perform Britney Spears' greatest hits, they learn that their own BRITTANY (Heather Morris) has a connection to the famous performer. Meanwhile, Will meets EMMA's (Jayma Mays) new love interest, DR. CARL (John Stamos), who sparks a rivalry between the two men as they vie for her attention.

The sophomore season of GLEE, the biting musical comedy that has quickly become a pop-culture phenomenon, kicks off tomorrow, Tuesday, Sept. 21 (8:00-9:00 PM ET/PT), with the "Audition" season premiere episode. After a tough loss at Regionals, the glee club is back as the underdogs of McKinley High. When the school is faced with even more budget cuts, Mr. Schuester pushes the kids to help recruit new members for the club. RACHEL (Lea Michele) and FINN (Cory Monteith) disagree on new recruits, including SAM EVANS (newcomer Chord Overstreet) and SUNSHINE CORAZON (international pop star Charice), and aren't sure they will be able to come together in perfect harmony. Meanwhile, Sue meets her match when she goes head-to-head with COACH BEISTE (Dot Marie Jones), the new head of the football team.