“Let it go
Let it go
Can't hold it back anymore
Let it go
Let it go
Turn my back and slam the door
And here I stand
And here I'll stay
Let it go
Let it go”

Demi Lovato – Let It Go Lyrics on LyricsMode
EXPLANATION
Don't Let Everyone or some other living thing ruin your dream.
EXPLANATION
Don't be afraid of what people will say about who you really are. Elsa has had to contain who she really is because both her and her parents didn't want Elsa's powers to hurt anyone else after Elsa accidentally hurt her sister. Elsa has revealed who she really is and can now finally just let it go and does not need to keep everything inside anymore. She is now free to express her powers and does not need to worth what other people will say or think about her.