Finding Dory, the follow up to 2003’s Finding Nemo, will be released this summer and we’ve just got our first listen to Sia’s theme song for the film.

It’s called Unforgettable, a reference to Dory’s memory issues which seem to be at the centre of the film, and the Australian singer premiered it with a live performance on The Ellen Show. The song is an adaptation of the Irvin Gordon written number of the same name, which was made famous by Nat King Cole.

After first listen, we're not sure. We like the song, but it's different to the more upbeat numbers usually associated with Disney and Pixar films. It feels like something that will grow on us with repeated listenings. You'll be able to hear it in the film, playing over the end credits.

Via Stereogum