Singer had described Nate Diaz's style as 'terrible'
Pop sensation continuing recent journey into dance music
Singer helped charity single to the UK top spot in December
Singer delivered a freestyle that didn't make the final cut
The almost-22-year-old singer had early celebrations this weekend
It's currently unknown whether the song was a leftover from his hit 'Purpose' LP
Sia, David Guetta, Faithless, Kaiser Chiefs, Bastille and Little Mix will also perform
Also featuring Lily-Rose Depp, Elisabeth Moss, Natasha Lyonne and Ellen Page
Stars pictured together at a Saint Laurent fashion show in Los Angeles
Singer also says he's well aware that he did some "dumb shit" when he was younger