The final Oscar nominee for Best Original Song is from Her and by Karen O of the Yeah Yeah Yeahs (I might be short a Yeah [CUE Grouch Marx "and it's the most important one"]).
I have no idea what the song sounds like because in the 30 minutes I've been on the iMac trying to run anti-malware software the video hasn't loaded and played. "But Macs don't get viruses" I hear you saying...
Song: "The Moon Song"
Artist: Karen O