Sia wrote her most popular single in less than an hour.

The 38-year-old star has claimed she penned 'Chandelier' - the lead release from her album '1000 Forms of Fear ' - in little over half an hour.

She told NPR: ''I mean, 'Chandelier' took like four minutes to write the chords, then like 12-15 minutes to write the lyrics.

''Probably 10 or 15 minutes to cut the vocals.''

She also discussed the way many pop songs follow a set formula, which largely centre on ''victim to victory'' tracks or ''party time'' hits.

She explained: ''The 'victim to victory' theory is that, if you listen to the radio, a large percentage of the hits are ... about victim to victory, like 'I'm having a terrible time.'

''And then the pre-chorus is 'I don't know what's gonna happen next.' And the chorus is, 'Now I'm brilliant, and everything is great, because something happened to make it great' ... Then,'' she says, ''there are songs like, 'Live like tomorrow doesn't exist.'

''About 50 percent of the songs on the radio are like, 'Live like tomorrow doesn't exist. Like it's my birthday. Like it's the last day of my life' ... Such a large percentage of pop music is really about party time.''