EDITOR’S NOTE — As bright as a sunburst is the face of a child who discovers how to whistle. But where have all the whistlers gone? Has whistling a happy tune become a dying art? It seems so, partly because much of today’s music doesn’t have a tune you can pucker up to.

BOSTON — “You do know how to whistle, don’t you? You just put your lips together and blow.”

That was Lauren Bacall’s husky parting shot to Humphrey Bogart in the classic film “To Have and Have Not.” But it seems hardly anybody follows that advice anymore.

Oh, sure, people whistle. You hear those ear-splitting shrieks at football games, the shrill blasts that beckon home wandering pets, the descending note of surprise, the appreciative wolf whistle.

But in many parts of the country it’s rare to hear somebody whistling a tune in public. Rarer still to hear it done well.

“It’s almost a lost art,” says Bill Taylor of Musician Magazine in Boston.

“It’s a throwback to a bygone era,” adds Harry Lipson, a Boston folk music promoter.

Earlier in this century, street-corner whistling simply mirrored popular music. Top performers — Bing Crosby, Al Jolson, Sammy Davis Jr., Jack Benny and folk singer Pete Seeger, to name a few — whistled in their acts, and amateurs picked up the tunes.

But the only one of that group still living, Seeger, no longer whistles in performances. “I haven’t heard him do it in years,” says agent Harold Leventhal.

Fred Taylor, a Boston jazz promoter, says some artists occasionally incorporate whistling into their acts. And a few avant-garde musicians whistle exclusively. “It’s in the novelty category,” he says. “It’s a cult.”

Among the faithful is Brad Terry who discovered his unusual talent about 25 years ago while standing in a cavernous Manhattan parking garage.

Terry, a jazz clarinet player from Brunswick, Maine, had just finished a jam session. While waiting for an attendant to deliver his car, he started whistling.

“It was extraordinary,” says Terry. “It had tremendous reverberation. There were 25 or 30 people standing on a platform behind me, and they all started applauding.”

Not long after that, he tried whistling with a microphone. “It’s been part of the act ever since,” he says.

Terry, who has recorded three whistling albums, is among the few professional practitioners of what appears to be a vanishing art.

Downbeat Magazine has called Terry “the finest jazz whistler in the world.” Another practitioner is Ron McCroby of Chagrin Falls, Ohio. An advertising executive by trade, McCroby has recorded jazz and classical albums and appeared on the “Tonight” show.

Meanwhile, a group of spare-time whistlers has tried for more than a decade to revive the dying art.

“Each of us had noticed that you don’t hear whistling anymore,” says Mimi Drummond of Horsham, Pa., who publishes a newsletter for the International Whistlers’ Association. “So we formed the association to promote whistling, especially among children.”

The group evolved from a whistling contest sponsored by the Chamber of Commerce in Carson City, Nev., in 1977.

About 30 people showed up to that first “Whistle-Off,” some whistling a cappella, some accompanied by piano, guitar, banjo, washboards, taped music and even live back-up singers.

Since then, the association’s membership has grown to about 200. They try to gather annually for a Whistle-Off but, as further evidence of whistling’s fading popularity, this year’s contest had to be canceled because they couldn’t find a sponsor.

Hard-core whistlers want to elevate whistling to a serious musical form. “We don’t do the bird-whistle competition,” says Drummond, a national champion who once performed “The Merry Widow Waltz” at a Whistle-Off.

At the same time, whistlers want to preserve the light-hearted spirit that prompted them to whistle, so they included a novelty category. One year a contestant performed while standing on her head. Others have whistled to the accompaniment of typewriters, kazoos and musical saws.

Whistlers call their art a form of self-expression that’s more socially acceptable than bursting into song in public.

“It’s nice to walk down the street and see people smiling at you,” Drummond says. “If you walked down the street singing `How Great Thou Art,’ you’d get carted away in a wagon.”

Technically, whistling is the sound produced by pushing air through the rounded lips. Whistlers can control pitch by moving their tongues and changing the flow of breath.

Beyond that, techniques differ. Most make music by blowing air out; a few, by drawing it in. Most pucker. Some smile widely as they whistle through their teeth. Some produce a reedy sound deep in their throats. Some whistle through their fingers, or their fists.

A few virtuosos can produce two notes almost simultaneously and some boast ranges of two octaves or more.

Whistling, so it is said, began as signaling. The earliest known whistlers were shepherds and sailors, who wanted sounds to carry great distances.

In the United States, whistling was a popular form of music-hall entertainment in the 19th and early 20th century. According to the Oxford Companion to Music an entertainer named Mrs. Alice Shaw, known as “La Belle Siffleuse” (The Beautiful Whistler), performed throughout the country as well as for European royalty.

Early in this century aspiring whistlers could study at Agnes Woodward’s California School of Artistic Whistling in Los Angeles. It’s gone, but there remain textbooks on the market such as “How To Whistle Like a Pro (Without Driving Anyone Else Crazy)” by David Harp.

Musician Fred Lowrey performed with big band orchestras, recorded a dozen albums and wrote his autobiography, “Whistling in the Dark.” Contemporary whistlers still perform his version of “Indian Love Call.”

Not everyone appreciated the art. A 1986 Smithsonian magazine article cited a 1931 complaint from Charles Shaw, a philosophy professor at New York University.

“Whistling is an unmistakable sign of the moron,” Shaw said.

Why has whistling faded to a mere echo of its former glory?

For one thing, Drummond says, much current music — rap, heavy metal rock, synthesized pop — doesn’t rely on the simple melodies that translate easily to whistling. “Even the Beatles are hard to whistle,” she says.

Whistlers acknowledge, reluctantly, that some people find whistling as annoying a habit as knuckle-cracking or pen-tapping.

Whistling also carries some negative connotations. Tattle-tales are whistle-blowers; a whistle-stop speech offers little substance. Some people “whistle past the graveyard” to cover their fears; cartoon characters whistle when they’re trying to cover something up.

Women have had to overcome additional anti-whistling prejudices. Victorian etiquette books declared the practice vulgar. In Louisa May Alcott’s “Little Women,” ladylike Meg exhorts sister Jo to stop because “it’s so boyish.”

Mimi Drummond quotes an old saying of uncertain origin:

“A whistling girl and a crowing hen

“Will surely come to some bad end.”