Backstreet Boys fans who couldn't get tickets to the band's residency at the Sphere shouldn't be too bummed ... as BSB member Howie Dorough just gave an impromptu performance while out and about in ...

Fans of the Backstreet Boys fans who happened to be at a Las Vegas venue this week — that isn't the Sphere — were at least able to see 20% of the boy band. And he even stepped up to perform solo for ...

Add Yahoo as a preferred source to see more of our stories on Google. Still, the Barbershop is known for having its fair share of surprise performances ... with the likes of Bruno Mars, Sir Rod ...