If they could only 'Whistle' up a plot

If anyone still wonders why the Encores! series needs to exist, a perfect response is "Anyone Can Whistle." At City Center is a splendid semi-staged performance of this infamous big-time flop - music by Stephen Sondheim, book by Arthur Laurents - which ran nine performances in 1964, but left a handful of vintage Sondheim songs and wheelbarrows of wistful curiosity. So now we know, and we know why we don't ever have to see the thing again.

The book is impossible - a cutesy-pooh pseudo-political satire about small-town corruption, a fake religious miracle, mentally disturbed people euphemistically called "cookies" and how, yes, the "crazy people are the hope of the world."

But with the brassy/classy Donna Murphy as the evil lady-who-lunches mayor, the goofy/glamorous Sutton Foster as the conflicted nurse and the nimbly incisive Raúl Esparza as the hopelessly hopeful stranger, it is hard to imagine a better case than the one made for the show by the gently whimsical director-choreographer Casey Nicholaw. The best-known music - "Everybody Says Don't," "With So Little to Be Sure of" and the title song - are like raisin and nuts on the road to the master who, six years later, would write "Company," and then an astonishing string of grown-up musicals.

Fully formed are the dry nervous rhythms, the unexpected harmonies, the unforgiving vocal intervals that require experts to pick unexpected notes from surprising places. Although Sondheim had already written both music and words for the atypical "A Funny Thing Happened on the Way to the Forum," he was still best known as the audacious lyricist for other men's music in "West Side Story" and "Gypsy."

Even in 1964, each song was its own little play with its own emotional trajectory. In the title song, "What's hard is simple, what's natural comes hard" is already a response to Sondheim's daunting intelligence. "Everybody says 'don't upset the cart' . . . but I say 'try,' " could be the theme song of his career.

The show is sharply dressed but less staged than many other Encores! revivals, which puts the focus where it belongs, on the music. Of course, when the imperious mayor, her fake miracle failing, commands, "We need a new plot line!" the laughter is too genuine to be polite.

WHAT "Anyone Can Whistle"

WHERE New York City Center, 55th Street west of Seventh Avenue, Manhattan. Through Sunday

INFO $25-$95; 212-581-1212; nycitycenter.org

BOTTOM LINE Wonderful early Sondheim, awful show