For “Fame Becomes Me,” which has 22 songs that could easily have been fashioned into a catchy opening medley, the decision was made by the clock. Scott Wittman, the show’s director, co-lyricist and co-conceiver said, “We wanted to get to the bar at Angus by 10.”  Audience stamina (and union work rules) can certainly make a four-minute overture seem a waste of precious time, but years ago it was almost required. From the modern musical’s infancy in the 1920’s through the so-called Golden Years in the 1940’s and 1950’s, audiences expected to sample a pu pu platter of great tunes, winningly arranged, as the lights dimmed from three-quarters to half and pink spotlights warmed the curtain. André Bishop, artistic director of Lincoln Center Theater, remembers listening intently to overtures when he attended musicals with his parents in that era — he’s now 56 — and “priding ourselves on spotting what would be the hit song from the show.” It didn’t always take much detective work because, in those days, Broadway songs were often pop hits before the shows began.  That era is long gone, but there was always more to the overture than the pleasure of the music itself. Practically, it provided a buffer for latecomers; dramatically, it helped to effect a mood transition from the outer world of commerce and cabs to the imaginary world about to be created onstage. It might hint at crisp sophistication (those four bright exclamation points at the start of “My Fair Lady”) or exotic doings (the pentatonic Orientalia of “The King and I”) or the possibility of louche women (the wild trumpet orgy of “Gypsy”). It could establish instantaneously the tone of the material, whether emotional (“South Pacific”), comical (“Bye Bye Birdie”) or satirical (“Candide”). In the case of the overture to “Candide,” that brilliant jack-in-the-box of musical surprises, it might do so better than the show itself.  But as musical theater grew away from operetta and aspired to be more like modern drama, and as its emphasis switched to storytelling instead of mere razzmatazz, the overture (which composers loved to write) began to seem out of place. For a few decades more sophisticated musicals occasionally finessed the matter with overtures that accompanied choreographed action, like Richard Rodgers’s “Carousel Waltz” and Frank Loesser’s “Runyonland” ballet at the start of “Guys and Dolls.” By the mid-1970’s, though, a theatrically daring show like “A Chorus Line” could dispense with the overture altogether. Defying its name in 1975 “Pacific Overtures” had only a wee prelude.  The emergence in the 1980’s of pop operas, like “Cats” and “Miss Saigon,” in which the songs were secondary to the brand, made stand-alone overtures seem even further off-message. (The brief musical sequence at the start of “Les Misérables,” which reopens on Broadway next month, serves mostly to accompany the famous advertising emblem of the waif Cosette, projected on a scrim.) More recently even traditionally conceived, melody-stuffed shows like “Hairspray” get straight to the action; its first song is preceded only by a 16-bar riff. “The Wedding Singer” is even more impatient: the curtain rises with the cast already dancing.  It’s partly a matter of the shows’ pop roots. “Rock ’n’ roll melodies played by a Broadway pit band without the vocals will often sound cheesy,” said Marc Shaiman, the composer and co-lyricist of both “Hairspray” and “Fame Becomes Me.” Mr. Shaiman is one of the most tuneful of today’s Broadway songwriters, but tunefulness, it seems, no longer justifies what’s often seen as an indulgence. “Because of the attention-span problem of the modern world,” he added, “everyone just wants to get right into the story. Even movies now put the main title credits at the end. And then, let’s be honest: you need Jule Styne-type melodies to really merit an overture. And a big enough band to play them. Why do an overture unless you’ve got xylophones going crazy?”  It’s true: you wouldn’t want to hear an overture played by a bunch of synthesizers. (It’s bad enough hearing the songs accompanied that way.) The orchestrators who turned Styne’s and Richard Rodgers’s melodies into the pieces that dominate our straw poll of best-ever overtures (see sidebar) had enough strings to sell the ballads, enough brass for the showstoppers. To create the many different effects that make Rodgers’s “Carousel Waltz” a masterpiece of abstract storytelling — eerie calliope sounds, nautical tub-thumping, huge romantic climaxes — the orchestrator Don Walker in 1945 had 40 instrumentalists to play with. “Fame Becomes Me” (not counting Mr. Shaiman onstage) has 8.  Smaller orchestras, lack of songfulness, shorter running times, all have contributed to the demise of the overture. But so have fundamental changes in the way audiences receive information. The set designer David Rockwell pointed out that, thanks to MTV, people now expect visuals with their music. For Mr. Bishop a related consideration is that overtures need curtains, and many Broadway shows, including “The Light in the Piazza,” which he produced last year at Lincoln Center, no longer use them. As a result the full “Piazza” overture was only played at the first few previews. “It seemed silly listening to lovely, lush melodies for five minutes while staring at the half-lit set, waiting for something to happen,” Mr. Bishop explained. Thereafter, audiences heard an abbreviated version of the overture, while leaves and lights and actors animated the stage.  That “waiting for something to happen” nails the problem. The traditional curtain-down, unstaged overture presupposed that music was already something happening, something capable, all by itself, of holding people’s attention. That notion has been sorely tested in recent years. Producers and directors say they doubt the audience’s ability to perceive useful information encoded in orchestral sound. Decoding that information depends on the habit of listening to music for its own inherent expressiveness, without words, pictures or action: a habit that disappeared from mainstream American culture along with the piano in the parlor. “Avenue Q” acknowledges that change: its “overture,” sung while a “Sesame Street”-like animation plays on video screens, is a ditty reminiscent of theme songs from sitcoms like “The Brady Bunch” and “Gilligan’s Island.”  Audiences in what Mr. Hamlisch calls “click world” seem uncomfortable unless all channels are firing at once. But this discomfort may paradoxically make overtures even more necessary. The director Gary Griffin said that, like most new musicals, “The Color Purple” started previews without an overture. At those performances, there was “an uneasy feeling when the curtain went up,” Mr. Griffin noted. “We’d had a focus group about the show, and people seemed to be troubled about how we were going to make this story” — based on a disturbing epistolary novel — “into a musical. But when we played them a sampler version of some of the songs, they all of a sudden relaxed into the idea and were ready to accept it. And I thought maybe this is what we should do in the theater.”  When the “Color Purple” overture was ready after three weeks of previews, the change in the audience was palpable, Mr. Griffin said. They seemed to understand how the music was going to function, and were prepared to listen to it for “details and textures,” not just as a delivery system for words. “It’s subtle,” he added, “but as orchestras dwindle in size, the more you put emphasis on their contribution, the better.”  So perhaps overtures can find a new purpose in helping to refamiliarize audiences with music as a form of storytelling. Call it a hair of the dog about to bite you. Certainly that’s how the director Walter Bobbie hopes the overture to “High Fidelity,” which opens on Broadway in December, will work. “Ours is a show about how popular music influences romantic life,” he said. “So I wanted to get the audience involved in that viscerally before presenting any words or ideas.” Apparently other directors and writers agree; in a probably short-lived mini-trend, two of the three new musicals expected in the spring (“The Pirate Queen” and “Curtains”) have overtures too.  At least they do as of now. But as Mr. Hamlisch could tell you, the best-made overtures oft times go astray. Sometimes even twice. His “Chorus Line” opener, rearranged and retitled “The Overture That Never Was,” was supposed to appear as a bonus track on the revival cast album, but has once again been cut. Still, Mr. Hamlisch, who was a protégé of Styne, didn’t cry much over the loss. For one thing, the number can be heard on one of his Boston Pops recordings. And for another, he said, the overture as a genre may finally be too rich a treat to revive. “It’s like French sauce,” he explained. “You enjoy it, but it ain’t healthy.”
Traditional Broadway overtures — several minutes long, made up of melodies heard later in the show and played by an orchestra before the curtain goes up — are disappearing.