It don’t mean a thing if it ain’t got that swing. Those words from the late, great Ella Fitzgerald (via Duke Ellington and lyricist Irving Mills) could just as easily describe the Houston Jazz Orchestra. At least once a month, the 18-piece ensemble belts out dynamic big-band music—swing, funk, fusion—for an audience of awestruck students, fellow musicians, show-starved jazz lovers, and curious onlookers who don’t know Woody Herman from Woody Harrelson.

Newcomers surprised to find themselves digging an HJO performance really shouldn’t be, explains president/lead trombone player Jim McLaughlin.

“It swings,” he says. “There’s something about the drum set and the energy and the positive vibe. Count Basie probably said it best in an interview with 60 Minutes. Morley Safer or someone like that said, ‘Can you describe your music?’ And he said, ‘Pat your foot.’”

Houston Jazz Orchestra dates back about 30 years; its current iteration has been going for about four, when House of Blues gave the band a no-cover monthly residency in its restaurant area. The members’ ages range from mid-twenties to mid-seventies.

Auditions are by personal referral only. A five-member Players Committee rules on all band-related matters, from repertoire to personnel. The 63-year-old McLaughlin, who’s in the construction business, thinks he may be the only current member with a “corporate day job.”

Many more are educators, including the heads of the TSU and Sam Houston State jazz programs and Warren Sneed, director of the Jazz Studies Program at Houston’s Kinder High School for the Performing and Visual Arts. But everyone is a “top-flight, ‘first-call’ freelance musician,” McLaughlin says. “There’s no hobbyists in this band.”

As a nonprofit corporation, HJO funnels much of its operating budget toward the periodic instructional clinics, often broken down by instrument, it puts on at Houston-area high schools. Jazz may be relatively obscure in today’s pop mainstream, but its power to dazzle aspiring musicians remains intact.

“When we played the first note of the first tune, I looked out into the audience and saw 100 kids and their parents. Their mouths dropped open,” says McLaughlin, recalling one post-clinic concert. “You could drive a car into their mouths.”

Besides the HOB residency, HJO does occasional out-of-town gigs like Beaumont’s Lamar Jazz Festival, coming up in April. The day McLaughlin spoke with Houstonia, the ensemble had just finished up three services at the Lone Star Cowboy Church in Montgomery County.

Rough-hewn dudes in Wranglers grooving to Maynard Ferguson and Stan Kenton tunes might be an unusual image, but “we’ve done it the last four years and they love it,” says McLaughlin. “They can’t get enough.”

The Houston Jazz Orchestra’s next performance, part of a monthly residency at House of Blues, takes place Feb 25 at 8. Free. 1204 Caroline St. 888-402-5837.