We couldn't include them all, but here are some of our favorites, including appearances by Bernadette Peters, Madonna, Angela Lansbury, Hugh Jackman, Barbra Streisand and more!

The Oscars love Bernadette Peters. Here she is in a tribute to Irving Berlin.

Madonna performing Stephen Sondheim's "Sooner or Later" from "Dick Tracy."

The cast of the Oscar-nominated film of "Dreamgirls" performing selections from the Henry Kreiger-Tom Eyen Motown musical.

Barbra Streisand performs her song "Evergreen" from the film remake of "A Star Is Born."

The video quality isn't so hot, but we had to include Bernadette Peters performing "Putting It Together" with some special Oscar-night lyrics.

Hugh Jackman is joined by Beyonce for this 2009 Academy Awards musical opener.

More Oscars! More Jackman!

Disco diva Donna Summer performs "Papa Can You Hear Me" from "Yentl."... yes, for real...

Angela Lansbury, Celine Dion and Peabo Bryson perform from "Beauty and the Beast."

The late Whitney Houston and Mariah Carey duet on the Oscar-winning Stephen Schwartz song "When You Believe" from "The Prince of Egypt."

Madonna sings "You Must Love Me" from the film of Andrew Lloyd Webber and Tim Rice's "Evita."

Kristin Chenoweth sings "That's How You Know" from "Enchanted," featuring a score by Stephen Schwartz.

Amy Adams also performs from "Enchanted" at the Oscars.

Before they were announced to co-star in the film of "Les Miserables," Anne Hathaway was singing a fun version of "On My Own" to Hugh Jackman at the Oscars.

Billy Crystal, who is back for the 2012 Oscars, performs a spoof of "Don't Rain On My Parade" authored by Tony-winning Hairspray writer Marc Shaiman.