Justin Bieber Leads Surprise Fan Sing-A-Long [Video]

Justin Bieber gave fans who waited for him outside The Late Show With David Letterman studio a ‘treat’ – an a capella version of his hit song ‘Boyfriend’ (his go-to track for minimal circumstances, apparently).

The 18-year-old singer, who is in the middle of a mammoth world tour, was driven to the studio in a black transit van with tinted windows.

Yet instead of rolling on past waiting fans like he had every right to, he stood in the vehicle’s open doors to conduct some small talk, asking where people had traveled from.

It was then he announced he’d be giving a rendition of ‘Boyfriend’, and the screams of appreciation quickly followed.

Accompanied only by an acoustic guitar, Bieber did his best to hit the high notes, only to be defeated by the pre-pubescent shrieking. But whatever you think of the singer, a nice gesture all the same.

And hey, it looked like the pint-sized pop star had a great deal more fun than with Letterman himself – as we reported earlier in the week, there was a distinctly awkward/hilarious feel to Bieber’s encounter with Grandpa Letterman, with the chat show later apologizing for being ‘snappish’ with the youngster.

Ah Dave, I thought you did well. Here’s Justin making his followers fangirl everywhere: