“Trad” jazz, the revival of jazz music from the early part of the 20th century, is an art with respect in some quarters and disdain in others. I’m siding with the former, mostly because it’s a stylistic niche where the music of another era is kept alive, a vehicle for showcasing the roots of jazz in real time. That and, in the right hands, it’s a lot of fun to listen to.

Those hands appeared on stage Sunday at the Albright-Knox Art Gallery (as part of the “Art of Jazz” series) in the persons of the Jim Cullum Jazz Band. Cornet player Cullum has led a band upholding this tradition for roughly 50 years and, since 1987 can be heard broadcasting from San Antonio on the Riverwalk Jazz radio program.

Cullum’s septet, an outfit that featured a mix of old and new players, played to a full house, displaying the wide range of musical possibilities that could be wrung from the 1920s and ’30s. These were the big years for the formation of jazz, the time when musical giants like Louis Armstrong, Fats Waller, Bix Beiderbecke, Jelly Roll Morton, and Duke Ellington helped create the foundation upon which the genre was built.

The concept of group improvisation was at the heart of the band’s playing, much as it was when their inspirations were walking the earth. While there was a melody, a rhythm and a set of chord changes for the players to work with, there were spots within the whole where individuals could shine as soloists and as part of a group taking flight from a common starting point.

Cullum and his cohorts on the frontline, trombonist Mike Pittsley and clarinetist Allan Vache, wove their way around a melodic stem, taking turns punctuating and accenting the basic structure, creating moments where the tripartite approach danced with the rhythm section even as they floated above it.

Pianist John Sheridan and drummer Hal Smith took turns anchoring the events, with Sheridan flipping between his role in helping provide a pulse and riffing on the core of the tune being played. Bassist Zack Sapunor and guitarist Adam Brisbin were the youngsters on stage but carried themselves well in the company of their elders.

Sapunor, who spent much of last year touring with honky-tonk hero Wayne Hancock, took a number of “slap” bass solos during the set but Brisbin’s steel-bodied guitar never managed to rise above the sonics of the band. It was as if the guitarist were fulfilling the same role that Freddie Green did for the old Count Basie outfit but without the carrying power. In that sense it was good that Cullum, during a break in the action, cajoled Brisbin into playing a little bit of Blind Willie McTell’s “Delia” to show what he could do.

But, when you get down to it, the music was the star of the show and the players did their best to put the spotlight on the material. Vache’s clarinet wailed on Ellington’s “Big House Blues”; Sheridan’s sly vocal take on “You’re Not the Only Oyster in the Stew” sounded like Randy Newman aping Fats Waller; and Cullum’s playing on Sam Coslow’s “Lotus Blossom” was lovely.

Before the concert began, Phil Nyhuis presented a talk entitled “Brass Deconstruction: The Cornet in Jazz History,” which helped set the historical scene for what the audience would hear in concert.