Anderson-Lopez and Lopez also composed a simplified pop version (with
shorter lyrics and background chorus) which was performed by actress
and singer Demi Lovato over the start of the film's closing credits.
Menzel's version was a single release, being promoted to adult
contemporary radio by Walt Disney Records in January 2014. Disney's
music division planned to release Lovato's version of the song
before Menzel's, as they did not consider Menzel's version a
traditional pop song.
The song's authors Robert Lopez and his wife Kristen Anderson-Lopez explain the differences in this interview with SSN Insider:
SSN: Pop star and former Disney teen star Demi Lovato sings the song
over the end credits. Was she chosen because she is already in the
Disney fold? (Lovato is signed to the Disney Music Group’s Hollywood
Anderson-Lopez: Because she is so damn talented. The Disney family
thing was very convenient, but honestly, she would have been at the
top of the list if she hadn’t been in the Disney family. “Heart
Attack” is one of my favorite songs of all time. Not everyone can sing
“Let It Go.” It’s not easy. She has the kind of voice that can.
SSN: What’s the difference between the two versions?
Lopez: The bridge. There’s a slight difference between the choruses.
It’s slightly rewritten for Demi Lovato. But the real change is the
part where Elsa is building the palace in the movie. It’s a totally
different section from the equivalent spot on the pop track.
Anderson-Lopez: But both versions tell a story of transformation from
fear of letting your power go to letting it come out. Idina will
always be our Elsa, and she tells Elsa’s story so well, but it’s very
story based. Demi’s is a little more metaphorical where the beat
starts driving and driving, but you still get the same feeling of
releasing all of this pent-up energy.