U2's song benefited from a high-profile television performance last week on comedian Jimmy Fallon's debut night on NBC's "Tonight Show," while Pharrell's "Happy" has been heavily featured in a Fiat television commercial. Both songs have been getting regular radio airplay, and both acts have been performing at private parties to drum up buzz during the two-week Oscars voting period this month.

Karen O teamed up with Vampire Weekend frontman Ezra Koenig for a duet on "The Moon Song," which received attention from fans online and was released in a three-song extended play album.

But all three songs may be dwarfed by Disney's "Let it Go," which has been helped by what Belloni calls "the juggernaut that is 'Frozen.'" The song has become a viral hit with more than 115 million views on YouTube and has helped the film's soundtrack top the Billboard album chart for five weeks.

In addition to that, Disney has benefited from sing-along versions of the film, which is storming toward making $1 billion at the worldwide box office, becoming the second highest-grossing animated film of all time. "Frozen" is also the frontrunner for best animated film on Sunday.

"It's in the tradition of the grand Disney musicals," Belloni said. "I think voters are going to look at that and they're going to say 'This movie is successful in part because of this one song,' and they're going to vote for it."