Sia Covers Nat King Cole's 'Unforgettable'

(Radio.com) Soundtracks are all the rage what with The Angry Birds Movie, Trolls and more children's movies featuring bigger and bigger names from pop, hip-hop and country.

Sia joins her fellow artists by contributing a song to the upcoming Finding Nemo sequel, Finding Dory. She covers Nat King Cole's "Unforgettable." As the voice behind Dory, Ellen invited the singer to perform it Friday (May 20) on her show.

"When I asked our next guest to sing the theme song to Finding Dory, I was thrilled that she said yes," Ellen said. Sia's version of "Unforgettable" sounds surreal as it combines the original's romantic melody with an underlying sense of whimsical childishness, which seems perfectly fitting for the film.

Wearing her black and white wig, which covers her face, Sia stood alone onstage in an elaborate black dress to sing the number. When Ellen joined her afterward to thank her for singing the song, Sia admitted, "Dory's story makes me teary." Read more here.