It's a few days until opening night. And on the stage of the Iron Gate Theatre, the teenage cast of the musical Thoroughly Modern Millie, part of the city Recreation Department theater camp, rehearses a scene.

The police have raided a speakeasy, and the fun-loving Jimmy - played by 15-year-old Tom Kuchler - is being hauled off to jail.

Kuchler saunters, his red-haired head bowed, his arms seemingly cuffed behind him.

Cue the music.

In jail, he sings "What Do I Need With Love," about his growing affection for the 1920s flapper Millie, as a group of theater campers dance around him.

Director Don Holdren watches for an emotional connection to the scene.

With only four weeks of rehearsals, he's also looking for things to tighten, lamenting, "We're down to the wire."

This month, Philadelphia's Young Performers Theater Camp will put on 16 shows at University of Pennsylvania theaters, for day campers throughout the city, as well as family and friends. The lights went up last week with The Pirates of Penzance at the Zellerbach Theatre.

The Wizard of Oz opens there Tuesday. Thoroughly Modern Millie opens Thursday at the Iron Gate. There's also a dance concert that night at the Zellerbach. The season ends Friday at the Iron Gate with a showcase by senior campers.

Aside from the shows, "students build self esteem and self confidence," says Tom Dignam, performing-arts coordinator. "Everyone works together, giving them social and life skills."

The camp started 36 years ago with a handful of students. This summer there are 345 campers, ages 9 to 18. Most are from the city. At the camp they select dance or musical theater as their focus.

The camp is perhaps the most diverse in the city. The students come from 108 schools and travel from 45 varied zip codes. Half are African American.

The six-week camp costs $30 a week, plus a $120 fee for a camp T-shirt, performance DVD, and costume. Bus transportation is available from some city rec centers, and there are scholarships.

With rehearsals, there are weekly classes taught by professionals and Recreation Department staff with performance-arts backgrounds. One dance instructor is a Rockette. One acting coach is a Barrymore Award winner.

Holdren, music director at Mount Saint Joseph Academy in Flourtown and a camp director for three years, says the program offers a model for production: a director, assistant director, music director, and choreographer.

Last year, one former camper played Sophie in Mamma Mia! at the Kimmel Center. Another is a senior at the Juilliard School on an acting scholarship.

There are 55 in the Millie group, ages 13 and 14, with two casts and two Millies.

Millie is a small-town girl from Kansas who goes to New York City during the Roaring Twenties for a new life. She bobs her hair and shortens her dresses, thrilled by the flapper lifestyle. She hopes to marry for money until she meets Jimmy, the lively paperclip salesman.

There are other bumps: white slavery, Chinese gangsters, and a love triangle.

When Holdren called 14-year-old Alivia Schaffer's name for the role of Millie, she was frozen in disbelief. It's her first year in the camp, and her first leading role.