Trey Anastasio

Trey Anastasio, Phish frontman, orchestral composer and guitar hero.

(Rene Huemer)

“I’ve always wanted to do this,” Trey Anastasio said over the phone. He wasn't talking about leading Phish, the great American jam band of its generation, but making music with an orchestra. On Tuesday, the guitarist will join the Oregon Symphony at the Arlene Schnitzer Concert Hall to make the world premiere of his latest piece, "Petrichor," as well as orchestral versions of material from across his catalog.

Anastasio studied composition in college in Vermont, which led to some of Phish’s early material, but he didn’t get the chance to work with an orchestra until years later, when the Vermont Youth Orchestra asked him to do a piece. For that, he turned to Phish's "Guyute," debuting its orchestral rendition in 2001. But "Petrichor" is an original, which began in the idle hours Anastasio had during final rehearsals for another project, Broadway’s short-lived “Hands on a Hardbody.” (Anastasio and Amanda Green’s original score earned a 2013 Tony nomination.)

“The writers have to sit in a studio for hours and hours and hours, it’s very laborious and time-consuming,” he said. "They’ll call you, they’ll need one tiny little fix. Like, they’ll say, 'Can we take two bars out of this line?' And you say, 'Yes, we can!'"

"Petrichor," an ode to stormy weather, began out of notes he made while killing time in the back of the theater in Nov. 2012, with finishing touches still coming the day of our conversation.

“My partner and collaborator Don Hart, with whom I’ve been working on these pieces together for 10 years, he’s currently orchestrating the ‘Petrichor’ piece right now,” Anastasio said. “We were on the phone this morning talking about one section.”

For all the time the musician’s spent exploring the possibilities (and then exploring them again) of a rock lineup with Phish, playing with orchestras, he says, makes him go weak in the knees.

“I get tears, virtually every time,” he said. “It’s completely 3-D and you’ve got the strings behind your head, the woodwinds over to your left and it’s just awe-inspiring. I go see the orchestra a lot when I’m in New York. If I’m going to see music with my wife, we go to the New York Philharmonic regularly. But I couldn’t anticipate what it was going to sound like standing up there.”

One of his challenges over the years has been to fit his electric guitar into acoustic symphony orchestras, which operate without the clatter of amps turned to "Spinal Tap" levels.

“It took a little while at the beginning to find out how to play at the right volume. I was trying to play at the volume of a bassoon or a trumpet,” he said. “I got to have coffee once with Michael Tilson Thomas (of the San Francisco Symphony), which was a thrill, and I asked him about how he conducts and he was telling me some interesting things. He spends a lot of the night trying to quiet the orchestra down. People probably think that a lot of the beauty of orchestras is when everybody’s pounding away up there. In reality, a lot of the emotion comes from space, you know what I mean?”

Anastasio will take "Petrichor" to Seattle and Los Angeles after its Portland premiere before another round of Phish dates: they’ll play one of their famous Halloween shows on Oct. 31, though after using last year’s to reveal new album “Fuego” rather than maintain their album-covering tradition, the guitarist says their tribute days are likely over.

“I don’t know that we’re going to cover anything this year, to be perfectly honest,” he said. “That’s the word I’m getting from the other guys. You never know. I’m guessing that we may have put that tradition to bed with the wink to ‘Fuego’.”

Asked how he stays energized and healthy on the road, Anastasio, who’ll turn 50 this month, says he made a big change this summer.

“I sort of moved onto my bus,” he said. “I don’t get off my bus. You’d be amazed at how much time that little move has created in my life. I’m not moving into hotels and back out of hotels and into hotels — this is my house. Right now my whole family is on the bus with me, my kids, my wife. We’re taking about four, five days to spend some time together.”

He was planning on arriving in Portland early, so if you see a Trey-look-a-like roaming the streets this week, look again.

“I love Portland, I love that part of the country,” he said. “I always find myself walking around, looking at art galleries, going to coffee shops. I love the food on the street. It’s a great city.”

Trey Anastasio and the Oregon Symphony, Arlene Schnitzer Concert Hall, Tuesday, 7:30 p.m. Tickets: $45-90.

-- David Greenwald