It's a school night and elementary to middle school students fill the seats of the Unicorn Theatre in Stockbridge, their belongings spilling over the closed chairs, their excited chatter cutting through the otherwise dormant theater.

"Focus, focus, focus! Concentrate on what you're about to do," yells Eric Hill, co-director and star of the Berkshire Theatre Group's "A Christmas Carol."

And just like that the mass of children quiet, quickly finding their spots on stage or in the wings. Like that they are theater professionals and the rehearsal begins.

"Eric wants you to connect with the story more than anything, so you can get deep with your character, even if you're just in the chorus," explains 13-year-old Emma Foley, of Pittsfield, before the nightly rehearsal for the community production began. "You always have to have a story. We'll be walking across stage and we have to stop and say, ‘Who are we? Where are we going?' "

Foley is one of the 28 local children -- ranging from 8 to 18 or 19 -- cast in the theater's annual production, which opened Saturday night, of the Charles Dickens classic, adapted by Hill, who also famously plays Scrooge. The youngsters' roles vary from Cratchit children to villagers. Foley was cast as Fan, Ebenezer Scrooge's sister who died in childbirth and appears as a vision of his past.

"I know, how uplifting," joked the well-spoken teenager, who is playing the role for a third year. "She was the only person who really loved Scrooge. When she died it made him who he is. Every year I try to go deeper, who is Fan? It's entertaining."

No matter the size of the role, the same level of professionalism is required of every child who is chosen from the October auditions to take part in the Berkshire County tradition.

"All of these guys are the best kind of actors you want to have," said Travis G. Daly, co-director of the show and associate education artist at Berkshire Theatre Group. "They are ready, they do their actors homework and they are really good on stage. They take the time to improve because they really care."

The schedule could be seen as somewhat grueling for the average kid -- with rehearsals six days a week, 6 p.m. to 9 p.m. weekdays and 10 a.m. to 5 p.m. weekends -- but these young actors don't seem to mind.

"I like doing it because I meet new people -- lifelong friends," said 13-year-old Mickey Mastrianni, of Great Barrington, who is in the chorus this year. "Also because you get to wake up in the morning and go on stage and be a completely different person then you are. It helps you figure out your own personality and who you really are."

As the rehearsal rolls from scene to scene, the younger actors not required on stage quietly file into their seats -- some pulling out homework, studying for a spelling test or finishing math problems, others doodle in drawing pads with a keen ear turned to the stage waiting for their next unspoken cue to return to the stage.

"They come in and they know all their lines and memorize the blocking like that," said Daly. "It's so inspiring."

Many of the children, like Foley and Mastrianni, have been in the community production before, which Daly attributes as one of the best things about "A Christmas Carol."

"It's awesome to see them grow," said Daly, who also runs the artistic side of the education program the theatre group offers. Even in warm-ups, he is coaching each child along with a kind smile, nod of the head or laugh. "Good volume!"

Sebastian Dowd-Smith, a sandy haired 12-year-old from Becket, has graduated this year to Peter Cratchit after playing his younger brother Tiny Tim a few years ago.

"It feels like I have more command," he said. "One year I was Tiny Tim, now I'm up a brother."

Daly compares the theater's investment in helping young actors grow to the baseball farm league system.

"It's my life," he said of the community productions the group puts on each year. "To me, it's one of most important things I do. We take these shows extremely seriously and have fun at the same time, with hard work and discipline. We want to have the kids surprise themselves and say, ‘Wow I can't believe I did that.' "

On stage, the kids aren't just learning lines and where to stand, they're also learning life skills they can apply almost anywhere beyond the spotlight. It helps one master public speaking, memorizing material and time management, said Daly.

"Theater can teach you how to channel and be disciplined with your creativity," he said.

"Time management is your best friend," said Foley with a giggle.

Daly himself said he continues to learn from the young actors year after year and from his co-director Hill, who the children also quickly praise.

"I've learned so much -- how to work with my body, how to connect with everyone on stage, facial emotions," said Mastrianni, who already has big Broadway dreams despite her parents' urging to consider all of her options in the many years to come before college. "It was a good experience being in it my first year. Even now, I'm still learning so much. Travis and Eric are great."

The production -- which runs at the Colonial Theatre in Pittsfield on Friday and Saturdays at 7 p.m. and Sundays at 2 p.m., with some special weekday showings at 10 a.m., now through Dec. 29 -- is a December staple for the Berkshire Theatre Group, but according to Daly, continues to change year after year.

"Little things always change," he said. "There are always different people in the major roles, so their personality is going to bring something different to the character."

Audiences can expect a new reveal of the ghost of Christmas past, and the largest cast the production has ever had, according to Daly.

"Come to see the kids who have really grown up with us take the reins in some big parts," he said.

Kids like Mastrianni, who after years of being on stage can make it difficult to remember she isn't even old enough to drive, yet.

"Being on stage makes you more mature, you know things you wouldn't have been exposed to otherwise," she said. "Being in a show keeps you in line."

If you go ...

What: Berkshire Theatre Group's ‘A Christmas Carol,' adapted by Eric HIll.

When: 2 p.m. Today; 7 p.m. Friday and Saturday; 2 p.m. Dec.22; 7 p.m. Dec. 27, 28; 2p.m. Dec. 29.

Where: The Colonial Theatre, South Street, Pittsfield.

Ticket price: 25-$35

For more information: To purchase tickets, call the box office at (413) 997-4444 or go visit www.berkshiretheatregroup.org.