Who sang the song "Let it go" from the movie Frozen?

Marshall, a great way to get rid of "let it go" being stuck in your head is to think of the song "I feel lucky" from Westside Story instead.

Great, now I've got that song stuck in my head again

I am not a number, I think you mean "I feel pretty". Doh.

Was it John Travolta that couldn’t pronounce her name?

And was Elphaba (the wicked witch) in the original cast of Wicked!