These children portray the young Von Trapps in the nationally touring production of “The Sound of Music,” now playing at the Kennedy Center. (Marvin Joseph/The Washington Post)

The most intricate and infectious moments in “The Sound of Music” belong to the kids. The notes of “Do-Re-Mi” pop like hot popcorn, as the jolly new nanny, Maria, teaches the hyper-disciplined von Trapp children how to make songs from a basic major scale. And then there’s all that giddy yodeling and hopping on a bed as the brood drowns out a scary storm with “The Lonely Goatherd.”

In the national touring company now at the Kennedy Center, the young performers could hardly be more charming as they croon “So Long, Farewell,” or more polished as they romp through their boisterous numbers. If they don’t entirely steal the show — and maybe they do — they certainly own the moments that will linger on the way home.

The von Trapplings, as the kids are affectionately known within this tour, which has lasted almost two years (and which concludes with a final week in Cleveland after its Washington stand ends July 16), range in age from 7 to 15. That grouping doesn’t include Paige Silvester, who at 26 is playing “I-am-16-going-on-17” Liesl.

Charlotte Maltby as Maria Rainer and the von Trapp children in "The Sound of Music." (Matthew Murphy)

Silvester was a replacement in the “Evita” tour that hit the Kennedy Center in 2014, and from the beginning she’s been Liesl in this respectful “Sound of Music,” directed by Jack O’Brien (“Hairspray”). The rest of these von Trapplings joined in January, except for Anika Lore Hatch, the 7-year-old who plays Gretl. She’s been touring since last August.

The budding pros seem attuned to the showbiz ropes. They follow directions quickly during a splashy photo shoot, and even though they travel with chaperons (usually a parent), none are supervised during interviews dealing with potentially touchy subjects — for instance, homework.

Least interesting question: how they make their demanding songs look so easy. Duh: When you know the notes to sing, you can sing most anything.

Anika Lore Hatch stars as Gretl. (Marvin Joseph/The Washington Post)

Anika Lore Hatch, age 7. Role: Gretl, 5.

Anika is from Tucson, and she is trilingual: English, Spanish and German. “My dad served on mission in Argentina, so I just spoke it,” she explains. “And my mom’s mom is from Germany. I learned so I could speak to my cousins in Germany.”

On tour, she enjoyed Sacramento for a reason that any Tucsonite would appreciate. “Sacramento is the city of trees,” she says, “and we don’t get that many trees.”

Touring is fun, although, Anika says, “it’s hard not to get sick, if you’re in airports and hotels and all over.” Pro tip: “I just wash my hands all the time.”

She played Gretl when she was 4 in a “Sound of Music” at the high school where her father teaches. Ask about her favorite theater, and she says: “I like this one. It’s really pretty, and there’s a lot of space. When they’re older, it’s really small backstage.”

What she likes about touring: “That I get to travel all over. I would never think that I would actually go to Canada, or here.” Also, “That I get to make people happy.”

Taylor Coleman. (Marvin Joseph/The Washington Post)

Taylor Coleman, age 11. Role: Marta, 7.

The San Diego native plays piano and violin and is a competitive gymnast. She eyes a long red-carpeted hallway outside the Concert Hall and says: “Since I’m not warmed up, I could probably do one round-off and three back handsprings right now. If I’m warmed up, I can do one round-off and seven back handsprings to a back tuck. There’s a video of me doing it. I don’t know where it is.”

As it happens, she’s old pals with castmate Elliot Weaver — they both appeared for three seasons in “How the Grinch Stole Christmas!” at San Diego’s Old Globe Theatre, where show director Jack O’Brien is artistic director emeritus.

Anything she doesn’t like about touring? “Leaving the tour to go home,” Taylor says. “I love it so much I never want to leave.”

She does admit to a challenge: “The first time I heard ‘The Sound of Music’ reprise, my harmony’s in the middle.” She hums a tricky line. “I’m like, I’m never going to be able to do this! But now I know it by heart.”

Field trips are scheduled at almost every stop for the kids, and Taylor liked the history of toys in Rochester’s Strong Museum of Play. The group’s visit to underground caverns outside Hershey, Pa., sounds memorable, too.

“It’s dark and kind of scary,” she says. “They asked us to sing, so we sang ‘The Sound of Music’ down there. It echoed. It was really cool.”

Dakota Riley Quakenbush. (Marvin Joseph/The Washington Post)

Dakota Riley Quackenbush

Age 11. Role: Brigitta, 10.

“I like all of them, except Rochester,” Dakota says of the tour cities so far. “I liked West Palm Beach, Florida. We got to go the beach between shows, and it was always warm. And Grand Rapids, because that was when my dad got to come see the show for the first time.”

Washington is special because the company sits down for five weeks. Until the show arrived here June 13, the year had been 16 one-week stands across the east and Midwest. “With one week,” Dakota says, “I feel like we just got here, and my mom’s like, ‘Pack your bags! It’s time to go!’”

She appreciates the musical’s reality as the von Trapps escape Austria during the Nazi rise. “It’s not a fantasy thing like ‘Cinderella’ or ‘Harry Potter,’ ” she says. “It’s nonfiction.”

Tough parts include having to finish fifth grade on the road, but she likes acting and will keep after it for a while. And yes, some of the work was challenging.

“When we did ‘Do-Re-Mi,’ I was like, ‘I’m never going to get this.’ There were so many ‘Tea, a drink with jam and bread’ in all these different spots,” she says, singing the line different ways. “But before you know it, I go on stage with ‘Tea, a drink with jam and bread.’ And it was pretty fun.”

James Bernard. (Marvin Joseph/The Washington Post)

James Bernard, age 11. Role: Kurt, 11.

James’s twin brother, Daniel, is such a good pitcher that baseball coaches want him for travel teams.

“He throws pretty fast, but I can catch him,” says James, a catcher whenever he gets to play ball. “When I perform, sometimes I feel nervous. But when I’m wearing the mask, I feel way more comfortable. It’s like I’m wearing armor.”

The New Yorker plays drums, clarinet and violin and is learning ukulele. “I also write songs,” he says. “I started that when I was 7. I write rock, pop, and I write instrument parts for them.” Being in “The Sound of Music” is a young composer’s dream: “Rodgers and Hammerstein’s work is phenomenal,” he says.

The tour seems like it’s a blast. “You get to see America!” James says. “Everywhere I’ve been has been awesome, but here is my favorite place. The audiences in D.C. are way better than any other audiences. They’re so enthusiastic! They clap during the overture at the beginning of act 2. That doesn’t happen anywhere else. My first performance here, I kind of got a little teary-eyed. I was happy. I got this far. I am at the nation’s theater.”

Stephanie DiFiore. (Marvin Joseph/The Washington Post)

Stephanie DiFiore, age 12.

Role: Louisa, 13.

How does this Westchester, N. Y., performer stay healthy through winter and spring on buses, planes and in hotels?

“I use the neti pot,” Stephanie says of the nasal irrigation system that, for some people, takes nerve to use. (Go ahead. Pour a pint of saline water up your nose.) “I was scared. But it works so well, and that’s the reason I haven’t missed a show yet. I also gargle.”

Basketball and softball are on hold for the athletic Stephanie while she tours. Performance-wise, she was ready for the road, but she says, “it gets tricky with homework. We have a shorter amount of time than the kids back home, but we have to do the same amount of work. By the time we get back to school, we have to be ready to go to the next grade. Sometimes it’s stressful.”

Getting everything right onstage “takes a long time,” she says. In “The Lonely Goatherd,” “simply moving that bed — you guys think we’re just moving a bed. That took like five rehearsals to get it perfectly moved to a perfect spot.” Still, she says, “the kids actually have fun. Especially ‘Goatherd.’ It’s not even like it’s a job.”

It is a job, and the kind she’d like to keep pursuing on stage and screen. “I want to keep it up until I guess I get bored with it,” Stephanie says. “As of now, I want to keep going, because it’s really fun.”

Elliot Weaver. (Marvin Joseph/The Washington Post)

Elliot Weaver, age 15. Role: Friedrich, 14.

“First off: everything,” the San Diego-based Elliot says about what he likes on the road. “Getting to be in the snow — that was pretty crazy. It was snowing a lot when we were in Waterbury, Connecticut. ”

Sitting in the owners’ box at a Washington Nationals game when Nicholas Rodriguez, the show’s Captain von Trapp, sang the national anthem was a perk.

“There’s only been one time where I was, ‘Oh, I miss home,’ ” he says. “It’s nice to have a family dynamic that my mom can be here. She can actually work on the road while my dad is back at home with my siblings.”

Homework? “It’s actually kind of easier,” says Elliot, who worked with the tutor connected with the show. Study hours are usually 10:30 a.m. to 2:30 p.m., although it’s summer break now. Outside interests used to include gymnastics, but that’s been refined to tumbling. Also now, photography on the smartphone.

The grind of the road? “It’s really not as hard as I thought,” he says. “But if I had to narrow it down, it’s just having to do the show even if you’re tired or not feeling well. You’ve just got to push through.”

Paige Silvester. (Marvin Joseph/The Washington Post)

Paige Silvester, age 26. Role: Liesl, 16.

“It’s been interesting to navigate,” says Silvester, a University of Michigan graduate who’s playing a decade younger than her age. She’s an adult, but she’s one of the kids. She’s a role model, but not the boss.

“I can’t be a disciplinarian; in essence, they’re co-workers,” Silvester points out.

Realities include not only chaperons for the kids, but a wrangler to keep them on track and an assistant conductor who ritually warms them up before the show.

“They’re kids; sometimes they goof around,” Silvester says. “But they’re all really respectful and kind to each other.”

“Do-Re-Mi” and ‘The Lonely Goatherd” are pivotal, she says. “They are about discovery,” , as the kids bond with Charlotte Maltby’s Maria. “It has to feel like the first time.”

She’s nearing 600 performances in “The Sound of Music,” a sturdy stretch for someone still making her name in the business. After the tour wraps up, Silvester heads back to New York to start auditioning — maybe something more dramatic or more modern.

“It’s felt good,” Silvester says. “But there will be a life after Liesl.”