Justin Bieber sings for screaming tweens in Long Beach

Wearing a gray knit hat that covered his signature hairstyle and a "Free Scooter" T-shirt as an homage to his manager arrested after a near-riot at Roosevelt Field mall, teen pop star Justin Bieber made hundreds of Long Beach Middle School students' dreams come true with a private concert in their auditorium Friday.

Girls screamed his name as he hit the stage for a five-song set that lasted about 25 minutes, and they sang along as he sang his hit, "Baby." Prior to the show that was closed to the media, Bieber, who People magazine has called the "World's Biggest Pop Star," held a meet-and-greet with a small group of girls who organized the charity food drive that won them the concert.

"If I had to choose one thing in my life - this would be it," said Jackie Gropper, 13.

Despite wearing a shirt that alluded to the arrest of his manager, Bieber declined to talk about November's episode at Roosevelt Field where he was scheduled to sign autographs.

Prosecutors charged Bieber's manager, Scott "Scooter" Braun, with reckless endangerment and criminal nuisance in connection with the incident. Island Def Jam Music Group senior vice president James Roppo, who was in charge of the event, was charged with four misdemeanors and one felony. Both have pleaded not guilty.

A representative from Bieber's camp told reporters not to ask about the incident and when one protested, the reporter was temporarily removed from the school, then allowed back in a short time later.

But Bieber did thank the school for hosting him and personally thanked the girls - Gropper, Chandler Gregor, Shannon Horgan, Liz Lieber, Brooke Lownfels, Maria Quintero and Dana Vargas - for organizing the collecting of food that was distributed throughout the community via Island Harvest. The school collected more than 27,000 pounds of food in the contest sponsored by radio station WXRK-FM, known as "92.3 NOW."

And he did talk about performing in a school auditorium. Bieber is scheduled to appear on this week's Saturday Night Live. He recently announced his first headlining "My World" tour, which stops at Madison Square Garden on Aug. 31, and released an album called "My World 2.0."

"I'm really glad I get to perform at a school," Bieber said. "It is one of my favorite things, being able to get intimate with the fans, get up close and have eye contact with them, and that is what I like."

Bieber performed in the auditorium accompanied by his guitarist who also played the piano, according to people inside the concert.

"I was watching the students' faces during the concert and you could see the joy in their eyes," said principal Audrey Goropeuschek.

Quintero, 13, clutched an autographed picture of Bieber and got to take a picture with him.

"It was so cool," she said.

Nassau County Police spokesman Sgt. Anthony Repalone said the day went off without a hitch - no unauthorized entries and no crowd control problems.

With Nomaan Merchant