You measure young maestros’ progress by the sounds their orchestras produce and guest conducting jobs they get. But with Jacomo Rafael Bairos, you must also study his smile.

Watch the video of his Latin Pops concert with Nestor Torres and the Malaysian Philharmonic Orchestra, and you’ll see his “I can’t believe they’re letting me get away with this” grin.

Observe the clip of him leading Orquestra Nacional do Porto Portugal through “La Vide Breve,” alongside gleeful kids making gestures big enough to send a 747 down a runway, and his beaming face seems to ask, “Is everybody else digging this as much I am?”

But catch him with the Charlotte Symphony Orchestra – say, in Friday’s KnightSounds “Ballroom” concert – and you’re likely to note a smile of calm contentment.

“This is the first year I have felt so comfortable in my skin,” he says at 36. “Now, more than ever, I have the feeling that I’m where I should be.”

Physically, he’s about to uproot himself again. Bairos, who’s leading more CSO concerts this year than anyone else, is in his third season here. He’s billed as “guest conductor,” after terms as assistant and associate, and he’s lining up orchestral auditions now.

Psychologically, the man who took 30 years to find his destiny has embraced it fully. He still enjoys the tuba, which took him from middle school bands to international gigs. Yet he loves the baton.

“Hearing a big orchestra, with all that sound and color and excitement, I always wanted to conduct,” he says. “But for a long time, I was scared to admit it.”

And Fate seemed to have chosen another path. Bairos, who was born in Lisbon to Portuguese-American parents, moved to Miami at 4. By the time he realized he wasn’t going to play baseball for a living, he had the tuba in his grip – and vice versa.

“We didn’t have a tuba player in our middle school bands. So I picked it up quickly, even though my stepdad had to carry the case, because it was bigger than I was. One day, our teacher took me to see the Canadian Brass, and I was mesmerized by the tuba player. He played standing up, told jokes, danced around onstage, did “Tiger Rag.” I thought, ‘I want to be in music, and I want to be this guy.’ ”

Half his wish came true: His tuba carried him to the competitive Arts Academy High School at Interlochen, Mich., the Juilliard School of Music in New York, substitute gigs with the New York Philharmonic, then a permanent post with the Singapore Symphony Orchestra.

“It worked perfectly for my hyper, outgoing personality,” he says. “It’s a way to add depth to double basses and cellos. It works well with horns. In 20th-century music, it matches a lot of bass lines. And I could sit at the back, watching all the musicians, and take in everything the conductor did.”

So why not BE a conductor?

First, most of them start as piano or string players, though horn player Esa-Pekka Salonen and trumpeter Gerard Schwarz defied the standard.

Second, Bairos always lived or studied with peers who seemed to be likelier conductors than he was. Third, he earned a fine living in Singapore without a baton: teaching, playing, directing the symphony’s chamber music series.

Then Fate changed its fickle mind.

Flautist Nestor Torres, whom Bairos had heard in high school, played a sold-out concert in Singapore for the Sôka Gakkai Buddhist community. Bairos asked the symphony’s general manager to set up a Latin Pops concert with Torres. The GM said sure – if Bairos could pre-sell the tickets. He went to Sôka Gakkai and got a commitment for $50,000 worth of seats.

“The GM asked, ‘Who’ll conduct?’ I said, ‘Me.’ ‘Do you have any experience?’ ‘Oh, sure, lots!’ But I hadn’t really conducted a full orchestra.”

His fellow musicians knew that, and some refused to play for him. He had to hire musicians from Hong Kong and Malaysia, and soon regional orchestras wanted him to repeat the event.

The Singapore Symphony decided to send Bairos to a master class in conducting in the Czech Republic. And at 30, he entered a new life.

“We studied French music there with Larry Rachleff,” says Bairos. (Rachleff will conduct the Charlotte Symphony here in March.) “Each time I went to the podium, I got better. My first ‘La Mer’ score looks like a 5-year-old’s coloring book, because I wrote all over it. But I came back the next day, and the orchestra clapped.”

At this point, Bairos’ late grandmother has to enter his story.

She’d owned a farm in Hendersonville, where the boy made summer visits. Now, as he prepared to lead the Debussy, “I felt her put her hand on my shoulder: ‘It’ll work out. You’ll be fine.’ It was a spiritual moment.”

That class earned him a chance to study conducting at Peabody Institute with Gustav Meier, whose alumni include heavyweights Marin Alsop and Antonio Pappano. But how to afford it? He had hefty debts from Juilliard and Cincinnati College Conservatory, where he’d gotten a master’s in music performance. Grandma came through once more: An inheritance from the sale of her property paid Peabody fees and put him on the road that led to Charlotte in 2010.

Why does he fit in well here?

“Jacomo caught my eye immediately,” says CSO music director Christopher Warren-Green. “Some conductors are not complete packages, but he was. We needed someone who’d engage with the community, who’d be doing a lot of youth work with the Lollipops Concerts, and he had the right personality for that.

“He was the applicant who really wanted mentoring; he had a hunger to learn. At first, a lot of his actions were heavy, because he’s a big chap, and the orchestra was slow to respond to them. In no time at all, he’d sorted that out. He’s a fast learner.”

Bairos half-jokes that “musicians are tough cookies. There was nothing more valuable that having them push my face in the mud! Trust has now been built between me and the CSO, and I know how we’ll (move) from the first rehearsal to the final concert.”

Composer-trumpeter Sam Hyken, a Juilliard grad and close friend since their Singapore Symphony days, calls Bairos “an incredibly sensitive and giving person. As Jacomo continues to grow, he has been able to refine these qualities in a way that makes him even more of an effective communicator. He has an amazing ability to be relatable to people of all ages.”

In love with the new

Bairos will conduct Hyken’s “The Beatles’ Guide to the Orchestra” for Charlotte students in March and cap his local career with “my zenith” on April 19: KnightSounds’ “American Music Masters and Pioneers,” featuring seven pieces from the last 85 years.

Bairos has always been devoted to new music, believing orchestras’ survival depends on “regeneration, continually reinventing ourselves and investing in new pieces. An orchestra is a live thing, and it has to change.”

He’ll lead the Tallahassee (Fla.) Symphony in March and the Amarillo (Texas) Symphony in April as a music director candidate.

“People don’t know what they want until they hear it. Esa-Pekka Salonen has said, ‘I wouldn’t play anything I didn’t love.’ And if you convey why you love it, audiences will agree with you.”