There comes a moment late in "The West Side Waltz," which opened last evening at the Barrymore, when Katharine Hepburn, chin tilted up and eyes shining, fantasizes about a waltzing, carriage-driven Viennese society, so unlike the grubby life outside her West Side flat. At this moment, she is once more Tracy Lord and Alice Adams and all the other radiant young women in her past. The moment reveals how much her rare talent is wasted, or circumscribed, in this second play about the elderly by Ernest Thompson, whose "On Golden Pond" (the movie, with Hepburn and Henry Fonda, is due Dec. 4) was vastly more amusing and trenchant.
Playing an increasingly disabled widow living in a roomy and obviously rent-controlled apartment (the play's six scenes span almost two years), she is limited to portraying a sharp-tongued, fiercely independent woman, qualities that scarcely test her capabilities. The play mostly has to do with Margaret Mary Ellerdice's (Hepburn's) gradual acceptance of her spinster neighbor, Cara Varnum, appealingly played by Dorothy Loudon. What the two have in common is music: Hepburn plays an ornately-painted grand, and Loudon the violin (some fancy finger-synching here to recorded music), and both have a fondness for waltzes.
Mingling with their lives is the building's super, a stock comedy Roumanian done ably enough by David Margulies, and a waiflike Brooklyn divorcee who calls herself Robin Bird and whom Hepburn takes in as a companion. As set forth by Regina Baff with a curious speech pattern, Robin sounds as much like a Brooklynite as Indira Gandhi.
The afternoons and evenings drag along so similarly that, having seen the septuagenarian heroine get about with one cane in the first scene and two in the second, our chief interest lies in what she'll be using in the next scene and whether she'll last out the play.
Hepburn gets off her retorts with polished ease, and Loudon's "Takes" are managed with familiar skill. The next-to-closing scene introduces a new character, or caricature, a young lawyer (Don Howard). Noel Willman has directed this sprung-sofa of a comedy tidily in a setting by Ben Edwards that reeks of seedy middle-class splendor. The Hepburn fascination remains intact, but Thompson should have done much better by the lady. "The West Side Waltz" is a play that undoubtedly would sell out if every day were Wednesday and every performance a ladies' matinee.
Presumably most people can grow old gracefully - it takes little more than a matter of grateful acceptance and thoughtful contemplation of the alternative. But to grow old gloriously, with all guns firing while churning along at full speed ahead, that is something different. It is a difference made manifest by Katharine Hepburn.
Miss Hepburn, and her enchanting co-star, Dorothy Loudon, opened last night at the Ethel Barrymore Theater in Ernest Thompson's The Waltz Side Waltz. But let me talk first about Miss Hepburn rather than the play - for it is Miss Hepburn that audiences are coming to see, and Miss Hepburn, not to mention Miss Loudon, that you want to read about. And so you shall.
She is playing a retired concert pianist living in a decaying, but grand apartment house on W. 72d St. The play, such as it is - for it is a vehicle more than a monument, or at least it would be if it ever moved - is spread over two years and reveals Miss Hepburn increasingly beleaguered in health, but consistently triumphant in spirit.
Personally I am never quite sure how good an actress the 72-year-old Miss Hepburn is, or, for that matter, was. It scarcely matters. It is certainly not relevant. She has created for herself a most remarkable ever-fascinating persona - and we have actually seen it grow up before our eyes, and we can still see the process in her old movies.
In West Side Waltz her smile is as radiant as ever - it still swoops over her face like a rainbow - her hair remains attractively frizzy, her voice retains that characteristic rasp that seems to suggest the outdoor life of dogs, horses and boats; while her personality, that sweet and sour sauce, continues to maintain its contrasted balance between innocence and the ornery. And, wonder of wonders, she is as girlish as ever.
The playwright Thompson appears to be fascinated by the geriatric life. His first success a couple of seasons ago was the mellow and beautiful On Golden Pond. It must be admitted that The West Side Waltz is a more flimsy structure and does not have the earlier play's homespun virtues. Yet Thompson does have a special knack for recognizable caricatures and for reality thickly disguised as fiction.
It must be admitted that not a great deal actually happens in The West Side Waltz. Yet it is no danse macabre and for the most part the characters, even Miss Hepburn succumbing first to a walker and then a wheelchair, remain pretty perky, and while revelations are not made, people are quite neatly sketched in a Norman Rockwell sort of fashion.
Thompson's major contention seems to be that the individual needs independence. Miss Hepburn demonstrates this when she rejects the offers of help and permanent companionship from the somewhat psychopathic Miss Loudon. The young and emotionally bruised woman (an agreeably tough performance from Regina Baff) that Miss Hepburn acquires from an advertisement to share her home, equally demonstrates it when she refuses to let the older woman manipulate her life.
Yet the play is here playing second fiddle to the acting, and in addition to the shining Miss Hepburn, and the no-nonsense modernity of Miss Baff, we also have Miss Loudon, vulgar and lovable, either stridently bright or with a pitiably crumpled face on the point of a Niagara of tears. Miss Loudon's shocking vulnerability appears all the more poignant against the patrician invincibility of Miss Hepburn and the wary canniness of Miss Baff.
There are two other attractive performances to fill out if not precisely flesh out the play. David Margulies makes a sort of macho ditherer out of a Rumanian-born superintendent and is very funny, and Don Howard is also good value as the daffy sociable lawyer who woos and wins Miss Buff.
And how do you direct Miss Hepburn? Carefully, I imagine. In any event Noel William has staged the play - not that it needed very much staging - with an entirely appropriate sense of claustrophobia, Ben Edwards's setting winningly conveys the seedy grandeur of an apartment that has known better years, and Jane Greenwood's costumes are, as is usual with this designer, uncommonly apt.
But the play is not the thing. In West Side Waltz it is the singers not the song that counts. And it is an unalloyed pleasure to cheer Miss Hepburn and Miss Loudon back to Broadway. Wouldn't they be wonderful in a musical version of Arsenic and Old Lace?
Ernest Thompson has written a tired play in ''The West Side Waltz,'' which opened at the Barrymore last night, but be assured that his star goes ahead and puts on her own vital show without him. Katharine Hepburn is at hand here, and Katharine Hepburn, in all her wonder, is what you'll get.
The actress ostensibly plays Margaret Mary Elderdice, an aging, widowed pianist who lives in a dreary Upper West Side apartment and wears dowdy cardigans that fall below her knees. While the playwright maintains that Margaret Mary is originally from Iowa, don't worry: Miss Hepburn's pronunciation - just hear the word ''pooper-scooper'' - remains the apotheosis of Yankee. It's also suggested that the heroine's health is failing - it's Mr. Thompson's wont to give her a new orthopedic appliance in nearly each scene - but don't believe that, either. Miss Hepburn, to say the least, is still yare.
Just how yare is first apparent not only in her robust face - gleaming eyes and those unmatchable cheekbones, all framed by a halo of graying curls - but also in her comic timing. When an overprotective neighbor tells her that it's too cold to walk in Central Park, Miss Hepburn waits one half-beat and announces, ''I'll run!'' The sheer finality of her delivery makes a so-what line very funny - and our laughter is capped by hers, which is contagious and open-mouthed and more-than-halfway aimed at herself. A little later, Margaret Mary is told of a man who is ''gay,'' and at first Miss Hepburn pretends not to know the current usage of that word. But the light soon dawns - brighter than any sunrise. ''Oh, ga-aa-aay,'' she says - and we see the same triumphant smile of mischief she gave James Stewart in ''The Philadelphia Story'' as she feigned not to know the location of his hometown of South Bend.
Then come the passion, the stubbornness, the vulnerability. Mary Margaret's best friend has killed herself, and someone asks why. ''Because she's a fool!'' cries Miss Hepburn, flying into a contained rage, complete with small fists. Then she adds, ''I won't forgive her for that,'' and her low, vehement voice quiets any fears that she might have softened her stand against spiritual weakness. Yet, as always, she's not really sanctimonious - she can fall off her pedestal, too. When a young woman doesn't immediately accept Margaret Mary's offer of a job, the actress's face drains of color in morbid fear of rejection. It's a glimpse of her Mary Tyrone, trying to retrieve lost love in the long shadows of a New London night.
Beautiful moments, all - and all Katharine Hepburn. Let's be grateful that Mr. Thompson feeds her lines and stays out of her way. Be grateful, too, that ''The West Side Waltz'' improves on the season's previous star vehicle, Claudette Colbert's ''A Talent for Murder,'' by placing its heroine in a wheelchair for only a scene or two instead of the entire evening.
But ''The West Side Waltz'' is otherwise a tedious retread of Mr. Thompson's previous effort, ''On Golden Pond.'' Once again this writer gives us an elderly protagonist, isolated and a bit embittered by old age, who learns to live again after a young companion (Regina Baff, as a would-be actress) moves in for an extended stay. And once again Mr. Thompson stands up boldly for the old verities. ''Human beings are not meant to be alone.'' ''If you want something in life, you have to go out and get it!'' ''Don't sell yourself short.''
It's Mr. Thompson who sells people short. Rather than create characters, he gives us types (two here have burlesque accents), walks them through contrived situations and then steps in to resolve their lives with divinely ordained happy endings. ''The West Side Waltz'' wants to be warm and poignant, but it's so coolly calculating it might have been written by computer. Margaret Mary's one flaw, selfishness, must be corrected by the final curtain - and, ipso facto, it is. Her companion must gain her self-confidence - and so she does. The other major character, a prim, virginal violinist played by Dorothy Loudon, is a prig for two hours, then kicks up her heels just before we go home.
These transformations aren't credible because they aren't dramatized. They either take place magically between scenes or are announced as faits accompli. The play's only real conflict - a fight between Margaret Mary and her companion - springs up out of nowhere and blows over about 10 minutes later. In a similarly arbitrary manner, Mr. Thompson suddenly bestows a lover on one character in Act II; his heroine's money problems, much discussed early on, simply fade away. Life is always neat and easy here: all six scenes end with Miss Hepburn playing a waltz at her piano and saying the same curtain line (''Now we're cooking.''). Such television-style tidiness cries out for commercial breaks.
The jokes are cheap and often compromise the characters, such as they are. (Would Miss Loudon's blue-nosed spinster really boast, ''I've never even had my period''?) Mr. Thompson's comic shtick, here as before, is to have elderly characters say - or overhear - expletives or sexual innuendos. This time he's also added some Neil Simon gags about such New York indignities as cockroaches and underheated apartments. Most of these are recited by a Rumanian - and inevitably malaprop-prone - superintendent.
Although Miss Loudon doesn't subside into broadness until Act II and David Margulies somewhat redeems the super with sweetness, the acting of the supporting cast is generally as mannered and thin as the writing. Noel Willman's direction contains no surprises: you just keep waiting for him to move his characters to the piano so each scene can end. But the star does keep you guessing about which part of her persona she'll reveal next - and there are more parts to her than most mere mortals around. While ''The West Side Waltz'' never gives us cause to look away from Katharine Hepburn, you might not be able to take your eyes off her even if it did.