PITTSFIELD -- The orchestra assembled before conductor Simon Brown is partial to wearing hot pink clothes and sneakers, and struggles somewhat to sit up straight.

Brown vies for their attention, reminding the elementary and middle school musicians that they have to practice being in "concert mode."

Tonight, the Kids 4 Harmony string and percussion ensemble will show their skills at the holiday concert schedule to begin at 5:30 in the Morningside Baptist Church.

There are now 36 children in the orchestra group, which began back in January with only 17 members.

During after-school rehearsal on Monday, newer students made more squeaky sounds with their instruments or got lost while playing, while the more advanced students' eyes would glance rapidly from their fingers to their instrument to their conductor and back.

"Here, we say ‘Passion first and precision will follow," said Carolyn Mower Burns, president and CEO of Berkshire Children & Families, which runs the Kids 4 Harmony program. Kids 4 Harmony aims to serve low-income families and schools.

It is based on a 37-year-old music and social justice music program called El Sistema.

Kids 4 Harmony also includes a preschool program called Sunshine Singers Choir, with more than 80 little ones.

There are plans to expand the program to more middle school students and students wanting to learn woodwind instruments next year.

Currently the program is run with three regular instructors, five high school assistants, an intern from Berkshire Children & Families, a graduate student evaluator from Westfield State University, and many parent volunteers.

Last semester, 7-year-old Natalie Mendez said she learned to play the violin, but is happier now playing cello "because you don't have to put your chin on it."

She said she liked learning "Jingle Bells" for tonight's concert, and proceeded to count and speak out rhythmic number patterns known as solfège.

The solfège for "Jingle Bells" is "3-3=3" or "mi mi mi," Mendez explained.

Asked how she feels when she's playing music, the second-grader said, "I feel happy that Mr. Simon teaches us every song."

There are many studies out there touting the benefits of teaching children music at a young age, but Claudia Paredes sees the benefits first-hand by watching her daughters Nicolina, 5, and Leila, 9, who are both in Kids 4 Harmony.

"I love music, classical more than anything. I wanted my daughters to have the opportunity that I didn't," the mother said.

Leila asked for and received a violin last year for her birthday. Just as her parents were looking for a program, Kids 4 Harmony was announced.

"The timing was perfect," she said.

Program director Alicia Stevenson said that the students meet after school each day for two hours, based on their skill level.

They also have a number of public performances, like tonight's holiday concert, each year.

Students must also earn good grades to stay in the program.

"My oldest struggled a little in reading but now she's doing so good. For my youngest, it will help her learn to sit still and to focus. She wants to be like her sister. It's motivation to keep doing well," Paredes said.