Sia covers The Mamas and The Papas' "California Dreamin'"

Given the film's dramatic leanings, the '60s pop staple has been transformed from a summer guitar-based tune into a piano ballad. Choirs, string quartets and vast dollops of reverb douse the orchestral cut. It's a far cry from the original, and Sia's typically crackling voice lends an entirely new atmosphere to the words.

You can hear the original version here.

Check out Sia's rendition below, or download it now via iTunes.