Gotye's duet with Kimbra conquered the world on Monday - well, the Grammys, anyway. But what makes Somebody That I Used To Know such a cracking pop song?
It's in many ways unconventional: there's a lot of whispering and not much rapping. It lacks a driving beat or catchy guitar hooks. You'd hardly call it shiny: at times it sounds dinky, even echoey.
Paul Kelly said: ''That song just had all the elements. It's a really great song and a really great clip. And it's a story that everyone feels.''
The heartbreak narrative is obviously part of the answer. The Record of the Year category at the Grammys might as well have been called the Broken Hearts Club.
The Black Keys' Lonely Boy, Kelly Clarkson's Stronger (What Doesn't Kill You), Frank Ocean's Thinkin Bout You and Taylor Swift's We Are Never Ever Getting Back Together all touch on broken relationships.
But, arguably, Gotye delivered a more universal experience - hearing two painful sides of one story. Gotye's character sings he ''felt so lonely in your company'', Kimbra's sings of ''all the times you screwed me over''. In the end, who's really right?
Blondie guitarist Chris Stein said his band had been ''playing that song endlessly''.
''It strikes a chord with people, there is a message in the lyrics [and] there is the back and forward between the guy and the girl. There have been a few songs that have tried that over the years but that has been the most successful.''