Al Pitrelli found a way to describe the Trans-Siberian Orchestra this summer when he was reading a biography of conductor Leonard Bernstein.

“He had a quote in there: ‘True art needs to be accessible, but never ordinary,’” Pitrelli said. “It kind of lit me up, and I read that passage a bunch of times over and over. I think that sums up Paul O’Neill and the Trans-Siberian Orchestra in one sentence.”

Pitrelli, a guitarist, has been with TSO since he was welcomed into the band by O’Neill in 1996 and now, after nearly 30 years of recording and touring, he knows precisely how the Christmas rock ensemble fits into Bernstein’s notion.

“It’s very, very accessible and it’s far from ordinary regarding the amount of different genres of music we perform — everything from Mozart and Beethoven symphonies through good old-fashioned American rock and roll, R&B, swing, choral pieces,” Pitrelli said. “And at the center of it is this incredibly sensitive, accessible but not ordinary story that Paul O’Neill wrote.”

The story for this year’s tour by TSO is “The Ghosts of Christmas Eve,” a rock opera created by O’Neill that follows the journey of a runaway who breaks into an abandoned vaudeville theater on Dec. 24. It will be the centerpiece of this year’s show, which comes Sunday to The Broadmoor World Arena, for a very good reason. “We’ve noticed that people have kind of embraced this as part of the holiday tradition,” Pitrelli said. “When we were kids, maybe it was ‘Charlie Brown’s Christmas’ or ‘Miracle on 34th Street’ or ‘It’s a Wonderful Life.’ ‘The Ghost of Christmas Eve’ has become that for many, many people, ourselves included.

“We’ve got a bunch of people in the audience that have been coming to see us for 20-something years now. They keep coming back and they want to see that familiar portion of the show. We’re gonna give that to them again, in content, meaning the poetry, the songs, the characters that Paul O’Neill had written into the story. But everything (else) about the show is different.”

That “different” part of the show is infused with the spirit and philosophy of O’Neill, who died in 2017. O’Neill’s way of doing shows figures into TSO’s elaborate visual production, which changes every year.

“Initially the decision on anything we do is ‘What would Paul think of this?’” drummer Jeff Plate said. “This tour every year is different and it is better every year and, in some aspects, it is bigger every year. This was something that Paull just insisted on doing. He was never going to run out with the same show year after year.”

What: Trans-Siberian Orchestra

When: 2 p.m. and 7 p.m. Sunday

Where: The Broadmoor World Arena, 3185 Venetucci Blvd.

Price: $39-$119.75; axs.com, broadmoorworldarena.com

Trans-Siberian Orchestra. Photo by Jason McEachern

Jason McEachern