Helium

Sia wrote and performed this orchestrated ballad for the Fifty Shades Darker soundtrack. The Australian previously contributed "Salted Wound" to the first Fifty Shades movie.

Sia wrote the song with her frequent collaborator English singer-songwriter Chris Braide, who has also worked with artists like Britney Spears ("Perfume") and Christina Aguilera ("Blank Page").

Sia sings during the song about the strength that she gets from being in a relationship. And if you let go I'll float towards the sun I'm stronger 'cause you fill me up But when the fear comes and I drift towards the ground I am lucky that you're around Sia is comparing the uplifting effect of love to the way helium lifts up a balloon.