I have to admit that I went to see A Tuna Christmas under some duress. This show and its ubiquitous predecessor, Greater Tuna, have become staples of community theater over the past 20 years, and I anticipated the performance ­ especially in the cavernous Procter & Gamble Hall at the Aronoff Center ­ would be distanced and without much humor. I was wrong.

Joe Sears and Jaston Williams, the show's authors, know their characters better than anyone (they wrote them for themselves, so they should) and they bring them to their larger-than-life presence in a way that mostly works. I found myself laughing at many of their now familiar caricatures.

I suspect that most audiences have some notion that the Tuna shows are about the oddball, small-town folks of the tiny burg of Tuna, Texas. Both are shaped similarly, beginning with a radio broadcast from the 10-watt radio station, OKKK, by Thurston Wheelis (Sears) and Arles Struvie (Williams). They talk about the town's small-change business and the local controversies that become grist for the balance of the show, and they introduce a variety of characters we'll be meeting again.

The show's gimmick is, of course that the two actors play all the characters. And much of the humor comes from one of them sauntering off-stage as the burly sheriff and coming back on as an overweight, elderly woman and the other quick-changing from an ex-convict ne'er-do-well to his stages-truck air-headed sister. I should add that several of these characters are so familiar that many audience members laughed and clapped as they walked on, even before they spoke. (Of course, characters in drag often evoke such responses.)

Sears and Williams have lived with the 22 characters of A Tune Christmas for so long that they caricatures have almost taken on a life of their own. As a pair of waitresses, Inita Goodwin (Sears) and Helen Bedd (Williams) ­ be assured the puns are totally intended -- who snatch the prize for Christmas display from the town's "socialite" Vera Carp (Williams) after 18 consecutive years of victory, the two will remind you of women you've been waited on in roadside diners across America. (Theirs is "The Tastee Kreme.")

A Tuna Christmas has only the thinnest of plots. There's a "Christmas Bandit" who keeps vandalizing or stealing yard displays; lots of suspects are offered, but who it is becomes part of the show's humor. There's the family strife in the Bumiller family ­ mother Bertha (Sears in a vivid green pantsuit with red accents) and her two children, the aforementioned ex-convict and the aspiring actress, plus their never-seen father ­ that leads Bertha to the play's final scene, a "wild night" at the Town Hall where she, a non-dancing Baptist, cuts loose with announcer Struvie (who advocates posing as a Methodist, since they can dance) in a moment of reckless abandon and tender emotion.

But such events are really just part of the string of comic vignettes strung together ­ loosely connected by a series of seven different Christmas trees that roll themselves on and off the stage: The aluminum tree with bulbs that keep bursting is a crowd-pleaser, as is the one that Didi Snavely decorates with used weapons, including hand grenades. The production overcomes the size of the Aronoff by placing a smaller frame within the big stage, bracketed by two old-fashioned cabinet radios. The two actors make their characters larger than life, and they fill up the space quite nicely with amplified voices and steady humor. The show never lags in two-plus hours.

Williams' Snavely is probably the funniest character of the bunch: A dealer in weapons with a smoker's gravelly voice, Didi has enough funny tics to keep audiences laughing for more than two hours: Noteworthy are her pause-punctuated "God ... damns" and her tuneless humming of Christmas carols, interrupted by long drags on a cigarette while the song continues silently in her head, to be resumed once the inhalation is over. This bit is repeated frequently, and you can almost hear the audience mouthing the missing words until Didi picks it up again. It gets a laugh every time.

A Tuna Christmas is calculated to do that, over and over. It's the kind of humor you'll hear on the radio, in fact, on programs like Gary Burbank's comedy bits on WLW. The comedy is lowbrow but well done, and that can be a lot of fun. In the hands of two veterans like Sears and Williams, it makes for a very entertaining evening. CityBeat Grade: B