Video: Lady GaGa, Beyonce and More Rock 'American Idol' Finale

Lady GaGa and Beyonce Knowles, who served as guest mentors on a previous separate week of "American Idol", were two of the many musical guests at the finale of the singing competition on May 25. The former was bathed in blue lights as she performed "The Edge of Glory", while the latter belted out a live version of "1+1" with red lights and smoke surrounding her. 

Appearing high atop the stage, GaGa was dressed in a long cape and a bedazzled headpiece which has chains hanging on it. The Mother Monster delivered the first verse of the song before ditching the headpiece to reveal a warrior-type outfit. Halfway through the performance, she was joined by saxophonist Clarence Clemons of Bruce Springsteen's E Street Band. 

As for Beyonce, the R&B diva sang piano-led ballad "1+1" in a solo set, showcasing a stunning vocal performance. "This is my favorite song," she said of the slow-riding jam which becomes the opening track of her upcoming studio album "4". Wearing a gorgeous long dress, she got standing ovation from the judges and audience at Los Angeles' Nokia Theatre. 

Before singing solo, Beyonce teamed up with the former female contestants of "American Idol" for medley of her hit singles. Pia Toscano, Karen Rodriguez, Naima Adedapo, Ashthon Jones, Thia Megia and Haley Reinhart performed "Single Ladies (Put a Ring on It)", "Irreplaceable", "Get Me Bodied", "If I Were a Boy" and "Deja Vu". Beyonce didn't join the girls until they charged into "Crazy in Love". 

Other performers included U2's Bono and The Edge, TLC, Marc Anthony,Carrie Underwood, Tim McGraw, Jack Black, Tony Bennett, Judas Priest,Kirk Franklin, Gladys Knight and Steven Tyler. 

Lady GaGa: 


Beyonce Knowles: 


Beyonce and "American Idol" contestants: 


TLC: