If NBC's strategy of "sneak-previewing" new sitcoms in cushy venues near already established, high-rated hits can pay off for the network on lousy shows like "Valerie" and "You Again?," two recent previewees, then maybe it will work with a good show, too. Tonight, with the sneak preview of "All Is Forgiven," NBC gets a chance to find out. By most yardsticks applied to TV sitcoms, this one is unusually tart and bright. It even sparkles.

Bess Armstrong, perky but not totally innocuous, stars as young TV soap-opera producer Paula Russell in the series, which gets sneaked tonight at 9:30 on Channel 4, right after "Cheers," then airs in that time period again next week, thereafter finally settling into its own time slot, Saturdays at 9:30 (where it can also enjoy a beneficial lead-in: "The Golden Girls," which ranked No. 4 in last week's Nielsen Top 10 even with a repeat episode).

In the opening installment tonight, Paula is about to marry her true love, Matt Russell (Terence Knox), a graying greening-of-America type who is riding the crest of the doughnut wave; his "Yin-Yang Doughnut," we are told, is a hit with consumers. Just at this precipitous moment, Paula also gets the opportunity to become producer of "All Is Forgiven," a daytime soap.

She decides not only to go for it, but to go for them. She's married on the set of the show at the end of her first day at work. The episode's climax, and Armstrong's closing line, are sweethearts.

Much about the program does seem ordinary. Characters and the actors who play them tend to overproject in that spine-chilling sitcom way. But the show is from the Glen and Les Charles think tank, where "Cheers" was born, and so it is redeemed by savvy touches. The Charles boys do seem to have built the proverbial better doughnut. There is enough that seems true and funny about the series to lift it above the usual.

Nothing contributes more to that impression than Carol Kane in the role of Nicolette Bingham, head writer on the soap and truly one of the rarest of earth's pixilated sprites. Kane seems to have been slightly influenced in her performance by memories of the late Gloria Grahame in her daffier, antebellummy roles.

Kane floats through the air like lost cotton candy, and every line is delivered with a daft infectious lilt -- as when she first meets Paula and asks, "Will you be my best friend in the world till the day we die?" There is an assortment of zanies surrounding the central characters in this program, but Kane is zaniness in excelsis. She approaches perfection.

Kimberly Hill wrote the premiere episode, which was directed by "Cheers" ace James Burrows, who with Glen and Les Charles is executive producer. One stock character, a sultrily surly 16-year-old stepdaughter played by Shawnee Smith, is almost instantly tiresome, and watching Paula grovel her way into the child's good graces isn't very funny. But with a little tinkering, even this can probably be made to work, and Smith has a nice wry insouciance.

Eventually, one assumes, there will be more generous glimpses of life backstage at the soap opera, although that territory seems to have been definitively covered in the movie "Tootsie." Most new sitcoms start off shakily and then have to be polished and refined, however, whereas "All Is Forgiven" makes its bow in admirably buoyant, completed form. It's the kind of show that is destined to be studied in sitcom-writing classes at UCLA, but which nevertheless can be savored and relished here and now.

Or here and there, where NBC scheduling has put it.