Sunday In The Park With George, Wyndham's Theatre, London <!-- none onestar twostar threestar fivestar -->

Painting by catchy numbers

If ever a production deserved a West End transfer it is Sam Buntrock's ravishing rediscovery of this 1984 Sondheim musical, which opened to rave reviews at the Menier Chocolate Factory in London last December. What made it special in that small-scale venue survives and gains in power in the larger, but still intimate Wyndham's Theatre, where the production glows like the labour of love it so movingly is.

A highly personal meditation on "the art of making art" and on the various types of cost this entails, the show is structured as a diptych. In the first half, we see Georges Seurat at work on his ground-breaking 1886 painting Sunday Afternoon on the Island of La Grande Jatte. The idling Parisians in the picture come to life in a series of droll vignettes before being manhandled, at the throat-catching climax, into the fused perfection of the finished work of art. Sondheim's flecked, jabbing score provides not only a musical equivalent of the painter's pointillist technique but a nagging evocation of his obsessive psychology that always preferred patterns of dots to personal relationships. Then, after the interval, we are spirited to contemporary New York where the artist's (fictional) great-grandson, a conceptual light-sculptor, is creatively stalled.

The production's achievements are many, and demonstrate true originality. In enchantingly witty projections, it finds a fresh visual vocabulary for the piece. For the only time in my experience, the second half no longer feels like a bitter, unnecessary postscript, but forges strong dramatic links with Act I. And Buntrock never allows the technical wizardry to overshadow the performances, which are superb. The authority of his take on the show is evident from the opening moments when an animated charcoal line darts across the virgin purity of David Farley's white-walled gallery set, only to be rubbed out for second and third thoughts.

A swag of curtain is magically transformed into a tree. The blank set is gradually filled with images of men sculling on the Seine and of bouncing cartoon canines conversing on miniature canvases. There's a haunting sense of the impermanence of natural beauty and of the fixing and revising power of art. The design flushes with russet hues for George's lovely duet with his elderly mother on this subject, where the melodic lines seem to have the dreamy downward drift of leaves in early autumn. And Wyndham's proscenium proves ideal for the beautiful frame-within-frame effects as when, in the haunting segue between the two periods, the painting recedes into its own iconic afterlife - seen in a photographic representation of the Chicago gallery where it hangs.

The graphics have bite as well as charm. Seurat's stage-managing of his human subjects into the positions needed for the ordered calm of his masterpiece is mockingly mirrored here in the great "Putting It Together" number where the cynicism of posh fundraising bashes is mordantly signalled in the visual gag whereby the American George leaves insincere, hobnobbing clones of himself all over the room he is strenuously working. If people were valuable to Seurat principally as objects on which light falls interestingly, human beings are important to his descendant's arid art only as commercial sponsors.

The consolations of the time-merged reverie at the end feel, to me, a touch spurious. Making a pilgrimage to the now bleak and industrialised Grande Jatte, George receives a transfusion of hope from the ghost of his forebear's lover. But this is thanks to a case of mistaken identity, not because he has now earned the right to it morally. Any misgivings, though, are overcome by the passionate conviction of the central performances. Singing with compelling ardour, Daniel Evans brilliantly captures the troubled single-mindedness of Seurat and the emotional disorientation of the 1980s George. Humour, warmth and an affecting mix of gustiness and sensitivity inform Jenna Russell's gorgeously sung portrayal of both Dot, the painter's sorely tried model and mistress, and her ancient granddaughter. You can understand why the production reportedly moved Sondheim to tears.

To 22 July (0870 950 0925)