Oscars: 'Let It Go' Wins for Best Song, 'Gravity' for Best Score

John Shearer/Invision/AP

"Let It Go" co-writer Robert Lopez becomes the latest member of the EGOT family, adding an Oscar to his three Tonys, two Emmys and a Grammy.

Robert Lopez became the latest member of the EGOT family, adding an Oscar to his three Tonys, two Emmys and a Grammy.

Lopez and his wife, Kristen Anderson-Lopez, won the best song Oscar Sunday for "Let it Go," the hit single from Disney's animated feature Frozen.

Steven Price won the Oscar for score for his work on Gravity. Both were considered favorites in their categories.

PHOTOS: Top 10 Movie Songs of All Time

The Lopezes delivered their thank-you's by alternating their way down a list of names, stopping at one point to sing "Happy Oscar to you/Let's do Frozen 2."

The song category has rarely seen such high-profile nominees whose songs became bona fide hits during the Oscar campaigns. This week, three of the four songs are in the Hot 100, led by Pharrell Williams' "Happy" at No. 1; the Frozen soundtrack spent four nonconsecutive weeks at No. 1 earlier this year.

The Oscar joins Lopez's Tonys for The Book of Mormon and Avenue Q, his Emmys for Nickelodeon's The Wonder Pets and the musical theater album Grammy for Book of Mormon. Richard Rodgers is the only other songwriter to win each of the trophies for composing; producer Scott Rudin was the last person to go for the cycle.

STORY: 'Frozen' Composer Robert Lopez on the Perils of Translating 'Let It Go'

The duo has several stage projects in the works, including an adaptation of Frozen. Their original musical Up Here is expected to be mounted in 2015.

For Price, a Brit, Gravity was the first film he has scored after working for years as a film editor. Both Price and the Lopezes dedicated their awards to their families. Said Price to his parents: "Sorry I made so much noise growing up."

Anderson-Lopez said "Let It Go" was inspired by their girls "and the hope that you never let fear or shame keep you from celebrating the unique people you are."