Composer-conductor Julian Wachner. (Megan Greenlee)

Julian Wachner bounds up to the podium, tall and loose-limbed and eager, dark hair flopping, teeth bared in a huge smile, as energetic and eager to please as a golden retriever.

Wachner is a conductor, or a composer, or a keyboard player, depending on which week and which city you happen to pick. He comes on stage pretty much the same way, and conducts with the same big, loose, convulsive gestures, regardless. His most recent outings were in San Francisco, first as a last-minute replacement conducting the San Francisco Opera’s new production of Handel’s “Partenope,” and then in a planned debut with the Philharmonia Baroque. But you could have seen the same thing at a contemporary music concert in New York, where he’s the music director of Trinity Wall Street. And you can see his style regularly in Washington, where he’s the music director of the Washington Chorus, and where he’ll lead Beethoven’s “Missa Solemnis” with the group Sunday afternoon.

Diversity isn’t necessarily an advantage.

“The elite choral types are like, ‘You’re not a real choral conductor,’ Wachner, 45, said the other day, sitting outside a coffee shop in downtown Washington between his San Francisco commitments. “I have members of my own baroque orchestra who are like, ‘He’s just a tourist. This [music] isn’t all he breathes. I’ve had that my whole life. ‘He’s not a real composer. He writes Gebrauchsmusik” — that is, music designed to be used and liked, such as flashy Christmas carol arrangements for the Washington Chorus. “And then: ‘Your music’s way too hard and complicated. No one’s ever going to want to listen to it or do it.’ ”

Gradually, though, Wachner is coming into his own. When he arrived in Washington in 2008, he was bristling with nervous energy, both eager and a little defensive about his role as choral conductor. Then, in 2010, the Trinity Wall Street job came along, giving him the ability to program and perform a wide range of music, both baroque and contemporary, in the heart of New York City. “I don’t know any other performing arts organization or church program that’s like this,” Wachner says. Audiences — and music critics — have enthusiastically embraced his programming.

Composer-conductor Julian Wachner. (Megan Greenlee)

Then, this fall, came “Partenope,” perhaps Wachner’s highest-profile engagement to date.

“I learned the opera on the trip out,” he said. “I had the first orchestral rehearsal the next day. Which was my birthday. So they all played ‘Happy Birthday.’ And it was really perfect, because they were schmaltzing it up, and I was like, ‘Thank you so much, okay. That’s the last time you are ever going to use vibrato.’ It was such a great way to introduce that topic, because everyone laughed.” (Vibrato, the pulsing beat that’s de rigueur in performances of the standard symphonic repertoire, is not part of early-music style.)

The upshot: a positive experience; a well-received production; and the ongoing question of whether Wachner is moving onto the larger stage to which he has aspired.

He is not universally well-reviewed. His gestures, like the man, are larger than life, and sometimes a little sloppy. “Wachner put his stamp on it throughout,” wrote Joshua Kosman, in the San Francisco Chronicle review of the Philharmonia Baroque concert, “for better and worse.”

But the cellist Matt Haimovitz, a friend of Wachner’s from the conductor’s days as head of the opera department at McGill University in Montreal, praises his musicianship. “The clarity in the baton, in his expression and his gestures,” he said by phone two weeks ago, speaking of performing a new concerto for cello and choir written by Luna Pearl Woolf, Haimovitz’s wife. “He knew how to work with the singers, but I felt also as an instrumentalist the clarity of the pulse.”

“He just has a big personality, an astounding high level of energy, and an incredibly positive attitude . . . and that’s infectious,” said Dianne Peterson, the Washington Chorus’s executive director, in a recent e-mail. “His creativity in programming has attracted new audiences. Our ‘Essential Puccini’ in 2009 was an enormous success and started the ‘Essential’ series.” She added, “The singers are dazzled by his talent, his extensive knowledge, his ability to command the podium and his highly engaging approach.”

Wachner has clearly been trying to figure out how to channel his talent and intelligence since childhood. His former stepfather, Robert Cole, worked as a conductor under the likes of Stravinsky and Bernstein, before taking over the presenting organization Cal Performances. His mother, Mary Spire, is a former pianist who became an instructor in the Feldenkrais Method, a form of bodywork that promotes physical awareness and that many musicians, in particular, prize. (Wachner is now a Feldenkrais instructor). Wachner was a choir boy at the church of St. Thomas from the ages of 9 to 13, but moved away from classical music during high school in New York, instead writing for a rock band, going to clubs, and working after school at high-end delicatessens in Manhattan. “I learned how to slice nova lox the old-fashioned way,” he says.

Music soon won out. Within a few years of arriving at Boston University, Wachner was holding down posts from organist and choirmaster at Boston University’s Marsh Chapel — regularly writing new music for services as well as playing them — to music director of the Back Bay Chorale. He was active, frequently reviewed — and eventually realized that he could remain at the same level for the rest of his life. He therefore pursued the job at McGill — and a dose of humility. “I got to Montreal,” he says, “the year Yannick [Nézet-Séguin, the Philadelphia Orchestra’s music director] became famous.”

Wachner soon acclimated to McGill, and Canada. Still, when the Washington Chorus position appeared, he was seriously considering quitting music and going into Feldenkrais full-time. Whether because of Feldenkrais, his current jobs, or marriage — his wife, Emily, is an ordained Anglican priest at Trinity, where they met — Wachner has mellowed since his D.C. arrival.

“Mellowed” is a relative term. Talking to Wachner is still like getting on a log ride at the amusement park; it’s easy and fun, and a lot of information comes at you very quickly. Just get him talking about his next piece with the Washington Chorus: Alberto Ginastera’s massive 1975 “Turbae ad Passionem Grigorianam,” which he describes as “wicked hard. It’s all twelve-tone. Gnarly.” He’ll conduct it in February at Carnegie Hall with both his choruses, and the National Cathedral’s children’s choir thrown in for good measure — 300 people on stage, he says, “which will give us at least 600 in the hall.” Then, they’ll record it, in time to release it for the Ginastera centennial in 2016.

“My mom was seven months pregnant with me when she did her master’s recital, and she played Ginastera,” Wachner says. “I think my music is informed by his music more than Bernstein. I want to do, in 2016 at Trinity, what I did with Britten” — that is, a year-long project of performing as much of the composer’s music as possible. “It’s harder [with Ginastera],” he concedes, “because all of his works are epic scale.”

“And then,” he says, after describing his Ginastera plans, “we have the little Ives Fourth on the first half,” and breaks out into a cackling roar of laughter at the audacity of performing so much great, unpopular music.

Got all that? And if you do: How can you resist going?

For all of his range of activities, Wachner is perfectly clear about what he really wants.

“When I look in the mirror,” he says, “I’m like, I’m a composer. And if I lose that, I’m screwed. And everything else has always been to support that habit.”

The Washington Chorus and Julian Wachner perform Beethoven’s “Missa Solemnis” on Sunday at 5 p.m. at the Kennedy Center.