"Sunday in the Park With George," which will have its television premiere tonight at 8 on Showtime, is a musical like no other. Even those who had come to expect the unusual from composer Stephen Sondheim found him outstripping their expectations when the show opened on Broadway in May 1984.

Here, after all, is a musical based on a 19th-century painting, Georges Seurat's huge pointillist masterpiece, "A Sunday Afternoon on the Island of La Grande Jatte." To the degree that it imagines who the figures in that painting might have been and explores the rocky relationship between the self-absorbed Seurat and his mistress Dot, the show spins a story of sorts.

But it doesn't pretend to a linear narrative or historical accuracy. Indeed, the second act is devoted to the tribulations of a contemporary American artist, named George, who may be Seurat's great-grandson, or so his grandmother Marie tells him. This George builds laser-spitting, multimedia constructions called "chromolumes," but his inspiration is running low and the "business" of art is getting to him. To renew himself, he returns to his spiritual homeland, the island of the Grande Jatte, where the ghost of Dot encourages him to "just keep moving on. Anything you do, let it come from you. Then it will be new."

That has always been Sondheim's credo, and "Sunday in the Park," while containing echoes of "Company," "Pacific Overtures" and "Follies," presents the composer in a new, surprisingly personal light. Essentially, it is a meditation on creativity -- the demands it makes and the toll it exacts; the trepidation and triumph involved in "making a hat, where there never was a hat," as an exultant Seurat puts it; the urge to forge ahead and at the same time connect with the traditions of the past. Indeed, "connect" is the operative verb. Behind the two Georges lurks Sondheim himself, asking with dazzling invention and his ever-astonishing lyrical dexterity how an artist relates to the world, to people, to a blank canvas or an empty page.

Although it ran for more than a year on Broadway and won the Pulitzer Prize, the musical never converted its succe s d'estime into widespread popularity. Despite the anthemlike beauty of "Sunday," which brings both acts to a swelling close, the score does not give an audience a lot to hum on first hearing. Much of it has a jabbing, atonal edge that echoes the brush stroke of Seurat as he dabs his canvases furiously with colored dots. The events in James Lapine's book are governed less by logic than by a kind of free association. In box-office terms, the rigor of art is just not the stuff to rival the high jinks of alley cats.

Tonight's telecast nonetheless is a welcome introduction to a work that grows in appeal and stature (and even musicality) with repeated exposure. In one respect, it is more immediately accessible than the stage version. By presenting the superb performances of Mandy Patinkin (the two Georges) and Bernadette Peters (Dot and Dot's daughter Marie) in loving close-up, it lends warmth to an enterprise that some have viewed as intellectually chilly. Sondheim has never been one to wear his feelings on his sleeve. But better than a theatergoer's eye, the camera is able to spot and focus in on the flickers of pain, the sweet regrets and the unspoken love in his characters' troubled souls. As a result, the emotional subtext is tantalizingly close to the surface.

But something has been lost, too. What was truly thrilling in the theater was the slow coming together of Seurat's painting. At first, the audience saw only a white stage, then the island of Grande Jatte in all the randomness of a typical Sunday afternoon. Little by little, as Seurat beavered away in his sketchbook, the set was modified to reflect the artist's vision -- a tree suddenly dropping down from the skies, a cutout dog popping up through the floor, a boat appearing on the horizon and, finally, the various strollers assuming the frozen and immutable positions of the celebrated canvas. A constantly shifting camera imposes its own fitful movement on the proceedings and tends to deprive the viewer of an inevitable sense of fruition. The majestic stage climax -- akin to the slow-motion blooming of a flower -- looks a bit fragmented and piecemeal here.

Still, there is more intelligence and innovation on display in this "Sunday in the Park" than you are likely to encounter in a month of Broadway theatergoing. Patinkin's remarkable performance is both limpid and densely concentrated, and he lends an electric charge even to the seemingly passive act of a painter contemplating his subject. Peters combines similarly contradictory qualities -- the wistfulness of the child and the voluptuousness of the woman; her pouting petulance never precludes the generosity of her heart. Dany Ivey, Charles Kimbrough and Barbara Bryne are also standouts as the unwitting models for Seurat's painting and, in the second act, latter-day museum denizens.

The real star of the evening, though, is Sondheim -- elusive, complex and unpredictable. In "Sunday in the Park," he is examining Seurat, but he's revealing himself. More than ever before.