For Delia Raab-Snyder, the process of learning and playing an instrument is about community.

"We wanted to make music a social activity," said Raab-Snyder, "because it is."

The director of Tune Up Philly, an after-school music-enrichment program, said: "It shouldn't be something that you sit in your room all day and do by yourself. We want future students to see that their friends are playing and that those friends are playing for the entire school at the concert and then performing for the church next door, and say, 'If they can do it, then so can I.' "

Tune Up Philly is one of five ensembles of the Philadelphia Youth Orchestra, an independent outreach program.

The concept is adapted from the Venezuelan music program El Sistema. Led by Jose Antonio Abreu, the program was developed to teach low-income children how to play and perform orchestra-style music. Famed conductor Gustavo Dudamel, who leads the Los Angeles Philharmonic and the Simon Bolivar Symphony Orchestra of Venezuela, attended El Sistema.

Tune Up Philly began in 2010 at St. Francis de Sales School in Southwest Philadelphia. It moved in 2011 to the People for People Charter School on North Broad Street, where Raab-Snyder, assistant director Paul Smith, and several mentors teach an assortment of wind, brass, and string instruments to 95 of the school's 529 K-8 students.

"When creating the program, we wanted to make sure that the principles of El Sistema were kept," said Louis Scaglione, president and music director for the Philadelphia Youth Orchestra, "cognitive social development using the discipline taught by classical music."

From 3 to 6 p.m. five days a week, Tune Up Philly students attend group classes at the school, taught by professional musicians committed to helping the students grow musically. An orchestra rehearsal with all the students in the program follows, led by Smith, where students practice for forthcoming concerts.

The first of three concerts will be Dec. 15 at the Greater Exodus Baptist Church, 704 N. Broad St., and is open to family and friends of the young musicians as well as members of the church and the North Philadelphia community. In addition to their public concerts, the students will perform at several North Philadelphia Free Library branches to promote literacy through music. Tune Up Philly musicians will also perform and mentor children at the Early Head Start program at Children's Hospital of Philadelphia.

"It's a special role," said trumpeter Khalif Winn, 11, "to be able to teach other people younger than you, or even older than you. It feels good when people know you because you did a good job at the concert."

Unlike El Sistema, Tune Up Philly is not free - enrollment is $100 to $150 for the year - but families pay what they can, and students are not denied entry based on their ability to pay. The program provides SEPTA tokens for parents and students to defray the cost of transportation.

After participating in Tune Up Philly, many students continue their commitment to music, applying to such programs as Musicopia or the Girard Academic Music Program.

"We're cultivating these experiences of leadership and mentorship for the student that uses music as their skill, their talent," said Raab-Snyder. "Students are showing that there is more to them than what people think they are."