Actor Josh Gad, voice talent for "Olaf" in the animated film "Frozen", poses at the 51st annual Publicists Guild Awards in Beverly Hills, California February 28, 2014. [Photo/Agencies]

A recent Grammy winner, a legendary rock band, a Broadway star belting out a girl-power ballad and an impossibly cool indie rocker have found themselves at the juncture of one of the most compelling Oscar races of the year: best original song.

It's a category that has drawn big names and some drama of its own, and a lot of buzz around one song in particular that many girls and their parents are now playing in their heads; "Let It Go," from Disney's blockbuster animated film "Frozen."

"The song category is the most interesting category in my opinion, and it's drawn the biggest campaigning this year," said Matthew Belloni, executive editor of trade magazine The Hollywood Reporter.

The best original song category drew attention early in the race when Oscars organizers revoked a nomination for "Alone Yet Not Alone," from an independent Christian faith movie of the same name, citing improper campaigning by the songwriter.

The remaining four contenders span a wide spectrum of genres: Grammy winner Pharrell Williams' upbeat R&B ditty "Happy" from "Despicable Me 2," Broadway star Idina Menzel's inspirational interpretation of "Let It Go," indie rocker Karen O's dreamy ballad "The Moon Song" from "Her," and U2's rock-infused "Ordinary Love" from "Mandela: Long Walk to Freedom."

All four acts will lend their star power on the Oscars stage on Sunday to sing the nominated tunes.