LENOX — As Boston Symphony Orchestra music director Andris Nelsons readies for his third summer at Tanglewood, the Grammy-winning maestro finds himself uncharacteristically nervous at the outset of the season.
He’s not worried about the BSO’s opening night performance of Mahler’s Symphony No. 2, July 7. Nor is he concerned about leading Wagner’s titanic “Das Rheingold” on July 15, perhaps the largest concert opera performance in the summer festival’s 80-year history.
The object of the conductor’s anxiety is a relatively low-profile concert this Sunday during which Nelsons will make his US debut on trumpet, an instrument he relinquished roughly 15 years ago, when he resigned his orchestra seat to become chief conductor of the Latvian National Opera Orchestra.
“I’m more nervous about this than conducting,” said Nelsons, who arrived here recently after conducting Dvorák’s opera “Rusalka” in Munich. “I’m worried to disappoint my colleagues and embarrass my teachers.”
Nelsons will play fourth trumpet in Sunday morning’s performance of a piece for brass by Richard Strauss, later joining BSO principal trumpet Thomas Rolfs and soloist Håkan Hardenberger in “Fanfare for St. Edmundsbury,” a small work for three trumpets by Benjamin Britten.
“You have to overcome dry mouth, a racing heart — it’s a lot of things,” said Nelsons, his instrument resting by his side. “I’m worried I’ll miss a note, or people will say, ‘What does he think he’s doing?’”
The world of symphonic music is populated with conductors who continue to play their chosen instruments, but for Nelsons the trumpet has been more of a homecoming. While he once practiced “until [his] lips were bleeding,” he didn’t pick up a trumpet for years as he ascended the symphonic ranks, becoming one of the world’s most sought-after young conductors.
Nelsons continued to harbor an affinity for the instrument, prompting Hardenberger, a soloist who has performed with Nelsons numerous times, to arrange one as a gift a few years back.
“I was shocked,” said Nelsons, 38, who gave his original trumpet to the orchestra in his native Riga. “The notes that came out that first month weren’t any good. I don’t know if it’s much better now.”
Nevertheless, the instrument stuck. Nelsons now tries to practice at least an hour each day, and visitors to his dressing room over the past few years are routinely greeted by the insistent sounds of the maestro’s trumpet.
“He’s a great natural player,” said Rolfs, who has been giving him pointers. “He plays exactly like you would imagine he plays: naturally, with beautiful lines.”
Unlike the nerves that accompanied his days as a professional trumpet player, Nelsons says he now uses the instrument to relax, likening it to yoga — a comparison with which not quite everyone agrees.
“Each time I come to orchestras where he visits as a guest they say, ‘What have you done?!’ ” joked Hardenberger, who said Nelsons could “really play.” “Our office is right next to the conductor’s room, and we don’t get a quiet moment!”
From that initial trumpet, Nelsons has expanded his instrument stable, collecting various trumpets, including a flugelhorn, and a pair of piccolo trumpets. He’s also expanded his collection of mouthpieces, estimating that he now has roughly 100 of the attachments.
‘You have to overcome dry mouth, a racing heart — it’s a lot of things. I’m worried I’ll miss a note, or people will say, “What does he think he’s doing?’’ ’
“He’s a mouthpiece hoarder,” said Rolfs, who gave Nelsons many of his early attachments. “For a long time I felt like I was his personal supplier in secret. He’d tell me what he wanted, and I’d go out and get it.”
These days Nelsons is more apt to stop by a brass store near Symphony Hall or to pick up a few while guest conducting abroad.
“It’s a disease,” the maestro admitted of his quest for the perfect mouthpiece. “When I was a professional, I didn’t have the money to buy the mouthpieces I wanted. Now I can afford them, but the problem is not with the mouthpieces. The problem is with me.”
For the past few years, both Rolfs and Hardenberger have been giving Nelsons informal lessons, assigning him exercises, describing methods, and giving him playing tips.
They aren’t too worried about his mouthpiece habit, they say, but there is one thing about Nelsons’ practice regimen that causes concern: the piccolo trumpet, which he keeps in heavy rotation.
“I tell him: You’re not allowed to play the piccolo too much,” said Hardenberger, who warns that the small instrument can cause the lips to tense. “But he’s a real trumpet player. He does like his high notes.”
“I told him to play five minutes a day on the piccolo and put it away,” said Rolfs, who takes the sound of Nelsons’ trumpet as an invitation to enter the conductor’s room. “But he doesn’t do that. You put it in his hand, and he just loves it so much he just won’t put it down.”
In advance of Sunday’s concert, at least, Nelsons seems to have heeded his teachers’ warnings.
“It’s fun, but it’s dangerous,” said Nelsons, who may give another trumpet performance later in the season. “I won’t play the piccolo until August.”
Trumpeter Rebecca Oliverio, a Tanglewood fellow who recently graduated from Boston University, said she was impressed with the maestro’s playing after sitting next to him at a morning rehearsal.
“He sounds great,” said Oliverio, who also studies with Rolfs. “It’s like normal. He’s such a great musician.”
But Nelsons isn’t planning to give up the baton any time soon.
“I’m enjoying it, but of course I’m not saying I’m a serious trumpet player,” said Nelsons, who will also conduct a piece by Richard Strauss at the Sunday concert. “It’s nice to remind yourself what it’s like to be in the orchestra.”
Rolfs, however, has other ideas.
“This conducting thing? It’s never going to work,” he joked. “I keep waiting for him to give up this hobby and get a real job, like being a trumpet player.”Malcolm Gay can be reached at email@example.com. Follow him on Twitter at @malcolmgay