The Off the Circle Theater Company, which lately has taken to specializing in small revues honoring various composer/lyricist teams, has hit upon its most likable show yet, "Thou Swell!"

This one delves into the 24-year collaboration between Richard Rodgers and Lorenz Hart, and while there's no powerhouse in the six-member cast at d.c. space, there are no sore thumbs, either. What you get, instead, are three guys and three gals who are increasingly pleasant to be around, as the revue wends its way through songs familiar ("Manhattan," "There's a Small Hotel," "The Lady Is a Tramp," "Falling in Love With Love") and not so familiar ("The Girl Friend," "At the Roxy Music Hall").

The material is unbeatable--smart, crisp and unfailingly witty. You will find in Rodgers and Hart little of the mawkishness that mars the Rodgers and Hammerstein collaboration. Climbing every mountain and following every star were not Hart's preoccupations, and it has to be assumed that his bracing cynicism helped keep Rodgers' lusher, riper sensibilities in check. But that much we know already.

The surprise at d.c. space, where "Thou Swell!" runs through Nov. 13, is one of performers creeping up on you, working their charms casually, making mistakes here and there perhaps, but picking right up and carrying on, eyes as penny-bright as before. By the end you are truly sorry to see them disappear for a well-earned rest.

Not everything is right. The exquisite Dawn Hill, for example, puts too much protest and too little pathos into "Ten Cents a Dance." Anthony Brienza, parodying Pavarotti in "Johnny One Note," simply adds a useless joke to a song that is funny on its own terms. And it seems utter folly to have Gretchen Weihe and Mike Giacchino attempt even a mini-version of the "Slaughter on 10th Avenue Ballet," especially since the Kennedy Center will be giving us the real thing in its upcoming revival of "On Your Toes." But any slip-ups are soon outweighed by the collective appeal of this cast, which makes even the greenness of youth ingratiating.

The format is straightforward. With Rob Bowman providing extraordinarily alert accompaniment on the piano, the performers merely take turns front and center. There's some doubling and tripling up now and again and an occasional number is dusted with choreography. But mostly director Fredric Lee has kept the emphasis on the songs themselves. If those songs are carrying the singers part of the way, somewhere mid-show, the singers begin to assert personalities of their own.

Weihe and Giacchino, who look a lot like the boy and girl next door, certainly have a spiffy time with "The Girl Friend." Bill Krause, the most retiring of this extroverted bunch, uses his quiet manner to full advantage in "I Didn't Know What Time It Was." And while tall, gangly Marianne Glass is just right for the love-spurned female in that comic duet, "What Can You Do With a Man?," she's not the obvious choice for the smoldering "Bewitched." Yet, using Bowman at the piano as her foil, she takes it on toward the evening's end with splendid results.

But it's when they all pool their resources that this show really takes off. As those three chipper songbirds of "Sing for Your Supper," the women transform d.c. space into one big jazzy birdcage. The full-cast rendition of "Babes in Arms" is rousing. And the medley that concludes the show is a peach that clearly indicates a Volume II is called for.

By then, you see, the performers have fully seduced us with their undaunted spirits and cheerful dispositions. "Thou Swell" is tricky that way. It starts out by pointing the spotlight squarely on the songs, knowing they're A-1, and then lets us discover in our own good time that these six kids are pretty swell, too. If you're looking for unexpected refreshment, look no further.

THOU SWELL. Words and music by Richard Rodgers and Lorenz Hart. Directed by Fredric Lee; musical arrangement and accompaniment, Rob Bowman. With Anthony Brienza, Mike Giacchino, Marianne Glass, Dawn Hill, Bill Krause, Gretchen Weihe. At d.c. space through Nov. 13.