NEW YORK, USA (AP) — Justin Bieber had an unplugged performance at the Apollo Theater on Monday, but it wasn’t intentional — a problem caused a power outage during the singing sensation’s big concert.

The singer was nearing the end of a private show in front of a packed house when the power for most of the stage instruments suddenly went out, said his manager, Scooter Braun.

“Then we hear the fire alarm,” Braun said by phone Monday evening. “Literally, the boy blew up the Apollo — he heated up the Apollo.”

But Bieber still managed to finish his show, with the help of fans singing along with him.

“What it turned into was an Apollo moment, like one of those impromptu things,” said Nina Flowers, the Apollo’s rep.

“It was one of the most special nights I have ever been a part of,” said Braun.

The power outage, which only affected the stage instruments and some lighting, occurred toward the end of the show. Braun said they were told the problem was supposed to be only a few minutes, but it stretched to more than 40 minutes.