BANGOR — People abruptly stopped in their Christmas-shopping tracks at the Airport Mall Saturday afternoon to marvel at the loud, low hum that shook the very walls.

“B flat,” repeated Jeffrey Priest, and at his command 30 musicians tuned their tubas and euphoniums to the same note, producing a sound unlike any ever heard before at the mall.

As Bangor’s first Christmas tuba concert broke into “Jingle Bells” for its opening number, shoppers paused in front of the All For A Dollar shop to linger and listen to the music.

By the time the melodious tune of “Adeste Fidelis” began winding its way through the circular tubings, a crowd had gathered. There were mothers with strollers, shoppers with carts, and children tugging at parents’ coattails. A group of teen-age girls found a spot on the floor and claimed it as their own as they plopped down to enjoy the music.

Toes started tapping as the band swung into “Deck the Halls.”

There was a wide variety of shapes to the instruments spreading their Christmas cheer. Some were smooth and polished, others dull and dented with age, but the sounds they all emitted were smooth, full and as radiant as the season they were celebrating.

Priest, who is head of the music department for the Old Town schools, directed the musicians, who ranged in age from 14-year-old Eric Moore of the Garland Street School in Bangor to Sam Wyman, 73, of the Bangor Band.

During a break between songs, the conductor told the audience it was being entertained by “the most famous tuba players in the Greater Bangor area.”

Band members included eight Old Town High School musicians, another five from Bangor High School, and one from Nokomis High School. Also joining the group was Gordon Bowie, director of the Bangor Band and a trombonist in the Bangor Symphony.

Most of the performers wore jeans and casual attire. About half of them wore Santa Claus caps as did the director. Some of the horns were decorated with garlands of greens and tinsel, decorative bulbs and candy canes.

With “Star of wonder, star of light …” still echoing through the halls, Priest used another break in the concert to thank Scott and Cindy Taylor of Taylor Music of Turner for sponsoring the band.

In an attempt to explain the strength of the vibrations being felt by the audience, Priest said that the instruments produce sounds in the low register.

“I don’t profess to have a scientific background,” he said, “but the wavelength is slow and wide and far apart in frequency. In layman’s terms, you can really feel those vibrations. The low sounds carry farther than the high sounds.”

He said the instruments might not have the volume to reach the other end of the mall to Rich’s department store, “but you can be sure they are feeling those sounds in Rich’s.”

The concert was part of a national series of concerts promoted by the Harvey Phillips Foundation, according to Priest. He said that while the group was performing in Bangor, Phillips was conducting a band of 600 tubas at Disney World in Orlando, Fla.

The Christmas tuba concerts were started by Harvey Phillips, a famous tuba player who about 15 years ago started a foundation to promote the tuba and the euphonium. The euphonium is a smaller tuba that produces mellower tones.

As composers commissioned by Phillips wrote the music for the first tuba concerts, they arranged the pieces such that the euphoniums could play the soprano and alto portions and the tuba could do the tenor and base segments.

In organizing the first Christmas tuba concert in Bangor, Priest said he was pleasantly surprised to see some musicians whom he had not yet met show up for rehearsal Saturday morning. They reportedly heard about the concert through a Harvey Phillips newsletter and decided to join.

The band practiced from 10 a.m. to noon at Old Town High School when most of the players saw the music together for the first time. A few of those participating had performed previously in Christmas tuba concerts in Freeport or Boston.

Priest was assisted by Chris White, who is director of the University of Maine Marching Band and the Pep Band. “He was a great help. He handled all of the registrations and directed the moving of all equipment, chairs, music stands and instruments.

“It was a thrill for all of those who performed. We will definitely be back,” said Priest.