Charles Bontrager admits he was a bit reluctant when longtime Tucson conductor Herschel Kreloff asked him if he’d be interested in leading the volunteer Civic Orchestra of Tucson.

Bontrager, who spent nearly 35 years conducting before he joined the faculty at the University of Arizona’s Fred Fox School of Music in 2007, respectfully declined.

“I liked sitting in the back of the band so to speak,” said Bontrager, who had joined the Civic Orchestra brass section early this year after leaving the UA in 2010 for medical reasons.

Four or five years back, he reunited with the trombone and euphonium, instruments he had not picked up in 40 years.

“I started playing the trombone and euphonium because I missed making music,” he said, but he didn’t miss conducting, not then anyway.

When Kreloff fell ill last winter, Bontrager stepped in to sub for the 86-year-old, who had stood behind the podium for 38 of the volunteer community orchestra’s 43 years.

Kreloff died in April and three months later, the Civic Orchestra of Tucson’s board of directors appointed Bontrager to take his place.

Even then, with months of working with the orchestra under his belt, Bontrager was reluctant.

“But I saw from sitting in the ensemble that they had an incredible dedication to playing for Herschel,” he said.

And he also saw that the musicians, many of them retired music teachers or aspiring young musicians, had a desire to exceed their own expectations.

On Saturday, Oct. 13, Bontrager will make his official debut as music director, leading the ensemble in a program of works by Mozart and Dvorák at Flowing Wells High School. Music students from the school will join the 75-piece orchestra for one work.

Bontrager, who taught music in the Flowing Wells district several years ago and has led orchestras of varying levels of experience throughout his career, said he has a fairly direct philosophy for making music: “If you ask players to do their best if not a little bit more, they sit up and rise to that occasion.”

“My philosophy with Civic Orchestra of Tucson is that we have a bunch of nonprofessional musicians ... and none of them are paid. They are in there to enjoy making music,” he explained. “The philosophy I bring to the group is if we’re going to do this, we should do it the best that we can.”

“This is a really viable community asset and its goal is to play concerts for the greater Tucson community,” he added. “I like to do things that are moderately challenging to the ensemble because if you don’t challenge them, they won’t grow. But I like to choose things that are within their grasp.”

Saturday’s concert, which will repeat on Sunday, Oct. 14, at St. Mark’s Presbyterian Church, kicks off the orchestra’s 43rd season. The group in December will perform a pair of concerts focused on American composers in Green Valley and Tucson. And next spring, Tucson pianist and UA prof Rex Woods will join them to perform Beethoven’s “Emperor” Concerto.

Admission to the concerts is always free and the orchestra puts on an instrument petting zoo to let youngsters touch and try out the instruments.

Contact reporter Cathalena E. Burch at cburch@tucson.com or 573-4642. On Twitter @Starburch