As a member of the orchestra for Alliance Theatre’s “Into the Woods,” William Anderson must make performing a top priority.

That means letting some things slide — like laundry, yard work and pitching in to help make dinner.

There are just so many hours in a day. And this viola player happens to be just 16 years old and a junior at New Creation Christian Academy in McDonough.

William is one of nine teenage musicians inside a whimsical dark teal house onstage, providing the musical backdrop for “Into the Woods,” the Stephen Sondheim musical that explores the hidden dangers lurking in classic fairy tales, including “Cinderella” and “Jack and the Beanstalk.”

There are two ensembles of nine musicians (one violin, two violas, two flutes, one cello, one bass, one clarinet and one keyboard) who take turns playing shows. Most of the young artists perform four shows a week, including two performances on Saturday or Sunday. Each performance lasts about three hours.

With the support of their families, these young musicians juggle performances, school work and extra curricular activities like marching band. The seniors in the group are finishing up college applications.

They have become proficient at making every minute count. They read on the school bus, eat in the car. Many leave their houses before 5 p.m. for the 7:30 p.m. performance and return home close to midnight.

“I don’t have much time, and it is a push, but my family is helping and this is a once-in-a-lifetime experience,” said William, who is also a member of the Atlanta Youth Symphony Orchestra.

The musicians range in age from 15 to 18, and hail from 18 schools across metro Atlanta. They were whittled down from 35 young artists who auditioned this past summer.

Night after night, matinee after matinee, the young artists, clad in preppy uniforms donated by Holy Innocents’ Episcopal School, play tender melodies onstage. With perfect timing, they make birds sing, voices soar.

When Carly Weikle, a 15-year-old sophomore at Northgate High School in Newnan, was asked how she does it, she says without hesitation: “Three cups of coffee and not much sleep.”

Not that she’s complaining.

“This has been such a neat experience,” said Carly. “Seeing all the work that goes into a show like this. And the people you meet. I love it. I will miss it so much.”

Despite the many repeat performances, the show, which runs through Oct. 2, still captivates her time and time again.

“I tear up almost every time I hear ‘No One Is Alone,’ ” she said. “And ‘Agony’ — I can barely play it I am laughing so hard.”

The musical journeys of these youngsters varies. Some were exposed to classical musical while they were in the womb. Others picked up music (relatively speaking) later in life.

William is one of the kids whose musical gifts were nurtured at a very young age. At age 2, he played on a little bitty violin; by 4 he was taking 10-minute lessons. He eventually switched to the viola.

Carly’s musical quest was more of a surprise. When she was about 5, she took piano lessons, but she didn’t practice and gave it up before long. Then, when Carly was in the fifth grade, it was time for her to pick an instrument to play at her elementary school. She was intrigued by the jazzy, warm sound of the clarinet. At first, she practiced 15 minutes a day, then an hour a day. By the time she was in the eighth grade, she found herself playing as much as four hours at a time. And she’s recently started taking piano lessons for a second time. ”

Susan V. Booth, artistic director of the Alliance Theatre and director of “Into the Woods,” said she wanted a student orchestra to underscore the message of the show: “Careful what you say; children will listen.” By being onstage, the youngsters serve as witnesses to the story, she said.

“These kids rock. They took on a huge task and they’re acquitting themselves gorgeously,” Booth said.

The members of the youth orchestra are not paid for their performances, but the experience is considered an apprenticeship opportunity. As a show of appreciation, the Alliance has also given $10,000 to the Atlanta Symphony Orchestra for scholarships for young students.

Meanwhile, William is relishing the moment with his family’s support. And while he’s shirked many of his household duties during the run of the play, there is one he still performs.

William’s grandfather has Parkinson’s and lives with the family, and every night the viola player helps the elderly man get ready for bed. Typically they perform the ritual around 11 p.m. but on performance nights, William gets home close to 11:45. As soon as he gets home, he plops down his instrument and helps his grandfather go to bed.

He may be just a kid. But he and the others are mature beyond their years — with and without their instruments.

Onstage

“Into the Woods”

7:30 p.m. Tuesdays-Thursdays and Sundays; 8 p.m. Fridays-Saturdays; 2:30 p.m. Saturdays-Sundays; Through Oct. 2. $25-$65. Alliance Theatre, 1280 Peachtree St. N.E., Atlanta. 404-733-5000, www.alliancetheatre.org