The jazz combo playing amid jumbled light fixtures at Construction Junction sounded too smooth for musicians ages 10 to 14. Their director Howard Alexander III, who teaches at the Afro-American Music Institute in Homewood, kept rhythm on a mismatched drum set.

As they played, people dropped by to drop off instruments they no longer use: keyboards, guitars, trumpets, clarinets, French horns, even a dulcimer. The instruments will be given to the institute and to the Hope Academy of Music and the Arts in East Liberty, where they will be loaned to students whose families can't afford to buy or rent them.

The collection project, Play It Forward, was the idea of Coleman Dougherty, 13, of Shaler, a seventh-grader at Winchester Thurston School, who jammed on his guitar yesterday with the combo from Homewood.

Exactly one month earlier, Coleman was bar mitzvahed at Temple Ohav Shalom in McCandless. He created Play It Forward for his required community service project.

"I've been playing guitar for five years and piano before that," he said. "Playing an instrument was so important to me that I thought that children who didn't have that privilege must be so sad. I decided it was my turn to give back. I wanted to give used instruments to those who couldn't afford one."

Coleman knew people who owned instruments but didn't play them anymore. The question: how to collect and distribute them.

"The idea was Coleman's, but we did use our network of contacts and resources," said his father, Chip, an attorney.

Friends who were professional musicians helped them find the recipient schools. Coleman's mother, Kathy, was a veterinarian for the pets of Mike Gable, executive director of Construction Junction, a nonprofit used and surplus building supply company in Point Breeze.

Because the company handles donations of used goods, Mrs. Dougherty urged Coleman to see if it could become a collection site for donated instruments.

Mr. Gable initially had visions of violins getting tossed around with two-by-fours.

"I steered him away from his original idea and suggested that he put together a one-day event as a pilot project," Mr. Gable said.

Less than an hour into the four-hour event yesterday, Coleman's sister Rachel, 16, was stacking instruments under a display table to make room for more.

Most Reform Jewish congregations require a community service project as a component of a bar or bat mitzvah, a ritual which recognizes those 13 or older as adults in terms of their faith.

Reaching that status "means they have Jewish obligations to fulfill. Among those obligations is repairing the world -- helping others, doing acts of kindness," said Rabbi Art Donsky, of Ohav Shalom.

Kathy Eller, of Wilkins, dropped off a guitar she hadn't played for 15 years. It was more than a matter of cleaning her closet, said Ms. Eller, director of a drug treatment program.

"In grade school I wanted to take violin lessons, but I couldn't because my family didn't have the money for an instrument," she said.

Inability to afford instruments is a bigger problem now than it was years ago, according to directors of both recipient programs. As school music programs disappear, so do low-cost rentals.

The Hope Academy serves 300 students ages 4-18 and "we have had to scramble not only to get scholarships for lessons, but to get them instruments," said Linda Addlespurger, director of the program at East Liberty Presbyterian Church.

The Afro-American Music Institute, which serves students of all ages, emphasizes jazz and gospel. It's been hard to recruit brass and wind players due to the cost of instruments, said co-founder Pamela Johnson.

"This gives me a chance to open things up to the kids who might want to learn to play sax, but could probably never afford it," she said.

One of the most needed instruments is the djembe, a West African drum, but by mid-afternoon none had come in. Mrs. Dougherty hoped that will change in the future. The family also hopes yesterday was just the beginning of Play It Forward.

"Maybe this will be something I will be able to keep going and turn into a nonprofit where it's an actual job," Coleman said. "I'm not sure. It's still an open idea."