‘Glee’ finale: 10 memorable performances over the years

After six seasons, a live show and a concert film, Fox's "Glee" is finally switching off the lights in the practice room and calling it a day. The two-hour finale airs Friday with an episode co-written by series creators Ryan Murphy, Brad Falchuk and Ian Brennan.

Though ratings for the onetime phenomenon have dwindled from the lofty heights of its second season, chances are good that lots of alumni will tune in just to see what happens to everyone. This is a show about high school after all, and reunions are par for the course.

While we bide our time until we can all tweet about it together one last time, here's a look at some of the most memorable performances the show has given us over the years.

"Don't Stop Believin' "

The song that showed what New Directions might, with work, be capable of. One of pop’s most durable anthems of youthful optimism, the song had its moment in 2009 on “Glee,” on Broadway (“Rock of Ages”) and in baseball stadiums around the country. Watch the video.

"If I Were a Boy"

Alex Newell played the transgender student Wade “Unique” Adams, whose bullying after being forced to use the men’s restroom in the fifth season episode “The End of Twerk” resulted in his powerful performance of Beyonce’s “If I Were a Boy.”

"Teenage Dream"

Kudos for creative orchestration of the Katy Perry hit for this version by the rival Dalton Academy Warblers. Significant because it introduced Darren Criss as Blaine, future cast member. Watch the video.

"My Man"

One of several Streisand songs performed by Barbra-worshipper Rachel Berry, it underscored the unhappy nature of the Rachel-Finn relationship at the time. Watch the video.

"Dream On"

The duel by Aerosmith song between Mr. Schuster and onetime rival Bryan Ryan (Matthew Morrison and Neil Patrick Harris) was funny, sung with complete commitment and made you think about Aerosmith in a different way. Why did Bryan Ryan never return? Watch the video.

"Defying Gravity"

The perfect song for "Glee" adaptation, and a lovely duet between Kurt and Rachel in the show’s first season. Both this song and “For Good” were memorable “Wicked” contributions. Watch the video.

"Single Ladies (Put a Ring on It)"

Chris Colfer became a breakout star with the show’s fourth episode, “Preggers,” in which his character, still not out to his father, tries to play off his love of Beyonce’s “Single Ladies” dance as a football move. While seeing Colfer perform the song was fun, seeing the entire McKinley High football team making the moves was sublime. Watch the video.

"Make You Feel My Love"

“Glee’s” breakout success was tempered by tragedy when one of its cast members, Cory Monteith, died of a drug and alcohol overdose. The series bid farewell to the character with the fifth-season episode “The Quarterback,” in which Monteith’s character, Finn, also died. There were many heartbreaking sung tributes in the episode, with the cast acutely feeling Monteith’s absence, but none as heartbreaking as Lea Michele’s performance of this Bob Dylan song. Michele was Monteith’s girlfriend in real life, making this a final, sad goodbye for that couple. Watch the video.

"Friday"

Teen movie veteran Eric Stoltz directed the second-season prom episode “Prom Queen,” which featured a peppy, much cooler version of Rebecca Black’s viral hit “Friday” performed by Mark Salling, Kevin McHale and Chord Overstreet. The prom scene in this episode is notorious in “Glee” fan circles for the backstory, where background performer Nicole Crowther tweeted a spoiler regarding the prom king and queen, getting fired and chewed out by producer Brad Falchuk in the process. Even four years later, fans are still talking about her on Twitter. Talking about her, not with her – she deactivated her Twitter account. Watch the video.

"Time Warp"

“Glee” became known for its episode-long tributes to favorite performers, but this second season episode was a extended riff on camp classic, “The Rocky Horror Picture Show.” Nothing touching about this moment – it’s just fun. Watch the video.

Times staff writer Kelly Scott contributed to this article.