The Destiny's Child star had already signed up to duet with Josh Groban on "The Polar Express" theme "Believe", and now she has agreed to sing the songs from "Phantom Of The Opera" and "Les Choristes" as well, reported imdb.com.
"Phantom..." star Minnie Driver was considered the obvious choice to sing Andrew Lloyd Webber's "Learn To Be Lonely" at the Oscars as she sang the tune on the film soundtrack but Knowles has stepped in to perform. She'll also sing "Look To Your Path" from "Les Choristes".
Meanwhile, rockers Counting Crows will perform their "Shrek 2" best song nomination, "Accidentally In Love". There is no confirmation as yet to who will sing the fifth nominated song, The Motorcycle Diaries' "Al Otro Lado Del Rey".