Watch Sia Cover Nat King Cole's 'Unforgettable' for 'Finding Dory' on 'Ellen'

Sia performs  on The Ellen DeGeneres Show.
Courtesy Photo

Sia performs "Unforgettable" on The Ellen DeGeneres Show.

Sia appeared on Ellen today (May 20) to perform her cover of the Nat King Cole standard "Unforgettable," the closing track to the upcoming Finding Dory film. Bathed in dark blue light reminiscent of the deep sea, Sia put her unique spin on the Irving Gordon-penned classic.

Sia was chosen by Ellen (who voices Dory) to perform the somewhat ironic theme song for Finding Dory, the Finding Nemo sequel focused on amnesiac Dory recovering memories of her childhood. "Dory’s story makes me teary," said Sia. "When Ellen asked me, I couldn’t refuse," Sia gushed as she stood alongside the voice behind the charmingly ditzy blue tang fish.

Get Sia's cover of "Unforgettable" when the soundtrack and film are released on June 17.