The super producer dances with Lupita Nyong'o, Meryl Streep and Amy Adams while the Yeah Yeah Yeahs frontwoman is joined by the Vampire Weekend vocalist who plays his guitar.
Pharrell Williams was among stars who performed at the Academy Awards. The singer took the stage at the event to perform his nominated song "Happy", which also serves as the soundtrack to animated movie "Despicable Me 2".
Wearing his famous big hat by Vivienne Westwood, the Grammy Award-winning producer made everyone happy as he energetically sang while being surrounded by a bunch of dancers. He then walked off the stage and approached stars like Lupita Nyong'o, Meryl Streep and Amy Adams who sat in the front row.
Karen O also performed her nominated song at the annual awards show. She invited Vampire Weekend's vocalist Ezra Koenig for a duet version of "The Moon Song" from "Her" movie. Looking gorgeous in a red gown, the Yeah Yeah Yeahs frontwoman sat next to Koenig, who played his guitar, in front of a moon backdrop.
Later in the show, U2 came out to perform "Ordinary Love" from "Mandela: Long Walk to Freedom" while Pink, wearing a floor-length sparkly red dress, sang "Somewhere Over the Rainbow".
Idina Menzel then graced the stage to deliver the live performance of "Let It Go", the "Frozen (2013)" soundtrack which won the Best Original Song award after edging out nominated songs by Pharrell, O and U2.
Karen O's Performance:
Idina Menzel's Performance: