Justin Bieber unleashes his inner rockstar in Metallica T-shirt

He's put a lot of effort into distancing himself from his teeny-bopper years.
And Justin Bieber took his efforts to the next level when he unleashed his inner rock star during his performance with Jack U at the Hard Summer Music Festival in Pomona, California, on Sunday.
The 21-year-old worked a new, grungy look as he hit the stage with US DJ duo Diplo and Skrillex for their headlining set in a grey Metallica T-shirt.

The graphic tee was approximately four sizes too big and had the ...And Justice For All lyrics 'their money tips her scales again' scrawled in white print across the bottom.

But Bieber didn't completely do away with his usual style for his guest appearance.

The Canadian hit-maker stuck with his trusty reverse snap back which kept his famous quiff in place as he cut some shapes on stage.

He also wore a pair of low-slung trousers and trainers - perfect attire for his energetic performance.