The organ is not what you would call an instrument of comfort and joy. For better or worse, its pipes and pedals are associated with funerals, "Phantom of the Opera" and the French composer Olivier Messiaen, master of sober mysticism.

The Canadian Brass, an ensemble that's been going out on tour for nearly 30 consecutive Decembers, has taken up the organ's somewhat dour reputation as a holiday challenge. This season, the quintet is making spirits bright with a little help from organist Eric Robertson.

Arkiv Music released "Christmas Tradition: Music for Brass and Organ" this fall. It's the Canadian Brass' ninth holiday album, following a long line of favorites that have often been classical best-sellers. The album features nearly two dozen carols, songs and "Hallelujah" choruses, and while Robertson won't be present when the Brass plays Thursday at Elizabethtown College, he'll be with the quintet in spirit. They'll be playing several of his new arrangements, sans organ, and approaching the classics in a fresh way as a result.

"We try to mix it up," said trombonist Gene Watts. "That keeps us on our toes."

The trombonist founded the Brass in 1970 along with tuba player Chuck Daellenbach.

The industry greeted the ensemble with skepticism. Chamber music was for string musicians, pianists and an occasional wind player. Watts and Daellenbach weren't about to let lack of repertoire stop them from forming an ensemble. From the beginning, their concerts combined clever arrangements with corny theatrics, and classical music has never been the same.

Watts proudly takes credit for his trombone's role in elevating the brass quintet to "acceptable" chamber status. (One of the Brass' most prominent musical progeny, the Empire Brass, attracted an enthusiastic crowd to Mount Gretna last summer.)

He's reluctant to boast about his own ensemble's popularity, yet there's no shrugging off the truth: The Canadian Brass is one of the most recognizable names in classical music, in part because the musicians tour so tirelessly each holiday season, sometimes even lugging Santa suits across the continent.

Daellenbach and Watts are the quintet's two constants. A total of 17 other musicians have filled the ensemble's ranks over the past 37 years. The latest addition is Manon Lafrance, a young trumpeter from Quebec.

As the publicity photo makes clear, she's female. What's not so obvious? She's the first female member of this eminent ensemble, and the Canadian Brass is noting the milestone with some junior-high-level jokes.

"This is the first Christmas that we've gone out on tour with a girl," Watts said.

He's not sure how adding Lafrance will affect the group's Christmas concert decorum. The Canadian Brass is notorious for its comic sketches, and the musicians are still debating whether to let Lafrance take over the female opera-spoof roles from horn player Jeff Nelson. Trumpeter Joe Burgstaller rounds out the the quintet.

The tour kicks off tomorrow in Toledo. Speaking earlier this week, Watts acknowledged that there was also crucial question of repertoire hanging in the air:

"We still haven't decided if we're playing 'Frosty' yet," he said with a chuckle.

On the road, the Canadian Brass must meet certain expectations. Arrangements can change, but certain carols must make the program. That's just fine with Watts.

"I look at Christmas as a time for nostalgia," he said. "You don't want it to change too much."

Canadian Brass, presented by Gretna Music, Thu. 7:30 p.m., Leffler Performance Center, Elizabethtown College, $35, $30, $22, under age 26 half-price, 361-1508.