Greater Tuna" is neither a recipe nor a fish story.

Holding forth Off-Broadway at the Circle-in-the-Square (downtown), it is a fictional panorama of the third smallest town in Texas and its environs. And every twitch and twang is right on target.

All of Tuna's inhabitants -- male, female, young, old, crazed and half-crazed -- are played by a remarkable pair of actors and quick-change artists named Joe Sears and Jaston Williams. Several of the New York critics have rightly found their gallery of small-town types to be hilarious, although that is a response New York likes to lavish upon anyone living beyond the Hudson. But "Greater Tuna" is also something more -- a folksy slice of life that turns increasingly surrealistic as the sun makes its way across the great open Tuna sky. If Thornton Wilder had collaborated with Diane Arbus on a portrait of rural America, they might well have come up with this evening.

The interconnected sketches usher us through a day in Tuna, as it transpires in various kitchens and living rooms, the local funeral parlor and the Baptist church, not to forget Radio Station OKKK (250 watts), which functions as the nerve center, as it were, of the community. It's a town where "Living With Radiation" can win second prize in the high-school essay competition, where Didi Snavely's Used Weapons Store flourishes by selling arms "guaranteed to kill," where the town judge passed away in his bed wearing a one-piece lady's swimsuit and where "Roots" is banned from the school library because it only shows "one side of the slavery issue."

But it's also the town where Petey Fisk, the sweet twerp who runs the Greater Tuna Humane Society, knocks himself out trying to save the town's mutts and strays and even the ducks; where Bertha Bumiller struggles heroically to keep home and brood together, and where even so forbidding a matron as Aunt Pearl Burras nurtures an ache in her heart for the judge who jilted her long ago. (Granted, Aunt Pearl has secretly vowed to sing over the judge's dead body. When the propitious moment comes, she bends over his casket and crows triumphantly, "Judge, I feel a song comin' on." Still, the ache is there.)

Williams and Sears, who wrote the script along with director Ed Howard, have an eagle's eye for the idiosyncracies that distinguish these weather-beaten creatures. What they don't have is a sense of superiority that would make "Greater Tuna" a cruel joke, indeed. Between them, the two actors play 20 characters--often with no more than a second or two to change the costumes that Linda Fisher appears to have pilfered from the best backwater closets -- and they play them with understanding and humanity.

Sears, the portlier of the two, goes from pot-bellied Sheriff Givens to buxom Bertha Bumiller merely by donning a chenille bathrobe and slipping a hairnet over his balding head. In the process, however, he is also changing souls, and the transformation is truly amazing. Williams, spindly and jittery, can strike a manic glint in his eye as quickly as an arsonist strikes a match, and his jagged energy is the perfect complement to Sears' rolling bulk.

The script tends to mosey, but at one moment or another, most of these lost lives overlap, which gives a basic structure to the evening. "Greater Tuna" is more in the nature of a drop-in visit to the outlands than it is a work of gathering drama. But it is funny because it is so scrupulously honest. And being so honest, it is also -- against any odds I would have extended beforehand -- curiously touching.

GREATER TUNA. By Jaston Williams, Joe Sears, Ed Howard. Directed by Ed Howard. Scenery, Kevin Rupnik; costumes, Linda Fisher; lighting, Judy Rasmuson. With Joe Sears and Jaston Williams. At the Circle-in-the-Square (downtown).