The birth of the swing era 50 years ago was more than the beginning of a notable chapter in the annals of American popular music. It also represented the first step -- although it was not recognized as such in 1935 -- in the creation of a promotion agenda for the purpose of building up a newly arrived pop artist. A half century later, such ballyhoo would often upstage the performer.

But long before promoters revved up the well-oiled multimedia engines that propelled Elvis, the Beatles, Michael Jackson or Madonna into the pop pantheon, the earliest model of the genre was being road-tested at the Palomar Ballroom, a prototypical dance palace of the 1930s, which stood at Second and Vermont in Los Angeles.

By the early '40s, when the swing craze fizzled out, its founding father, Benny Goodman, had become a media celebrity -- thanks to radio, records, movies, tumultuous personal appearances, extensive coverage in the general and show biz press (prodded by flacks who cranked out news releases) and a legendary concert at Carnegie Hall, where he was the first pop artist in history to play on its stage. In 1939, Goodman was accorded the ultimate recognition with a gushing profile in The New Yorker, not known for often bestowing its elegant prose on arriviste entertainers.

Later that same year, in his autobiography, Goodman called attention to a personal appearance tour in the spring and summer of 1935. He noted it was turning into somewhat of a disastrous trek as his entourage moved westward. Word of how badly the band had bombed in Denver reached Palomar management and only a heroic effort staved off a cancellation of that booking. Recalling his apprehension on the band's Aug. 21 opening night at the Palomar, the 26-year-old Goodman wrote:

"All this was quite new to us, and we didn't know just how to handle it . . . We took things kind of easy with the opening sets, playing some of the sweeter tunes and sticking to the softer arrangements . . . But the crowd as a whole didn't seem very responsive. This went on for about an hour, till I decided the whole thing had gotten to a point where it was make or break. If we had to flop, at least I'd do it my way."

"My way" was the use of the Fletcher Henderson arrangements from the "Let's Dance" show. To Goodman's amazement, half the crowd stopped dancing and surged around the stand.

The crowd reaction settled it for Goodman: "After traveling 3,000 miles we finally found people who were up on what we were trying to do . . . The first big roar from the crowd was one of the sweetest sounds I ever heard in my life -- and from that time on, the night kept getting bigger and bigger . . ."

The Goodman group's Palomar engagement -- originally contracted for a month and extended through October -- is correctly credited with setting the swing generation in motion. In the months that followed, adoring fans worshiped at Goodman's shrine as the media pursued the swing story ad nauseam.

Goodman's description of his Palomar premie re, however, should not leave the impression that the acclaim from his first Los Angeles audience was caused by spontaneous musical combustion. Rather, thanks to some advance hype -- modest by today's standards, but hype nonetheless -- the Goodman forces were able to activate a new pop music movement and give it impetus in a relatively short period of time.

Radio, that midwife of rock and so many other musical species, was crucial in getting swing off the ground. Indeed until it was airborne, the music had a small audience and a large identity problem. Still, getting a program of swing music into network prime time during the mid-'30s was no easier than cracking the three major television networks in 1985. Popular music figured heavily in many of broadcasting's early sales successes, but advertising agencies preferred the safe commercial variety dispensed by the Clicquot Club Eskimos, the A&P Gypsies, the Ipana Troubadours and the Lucky Strike Dance Orchestra. By 1930 pop music was the dominant program type on all three major networks. (When he testified before a Senate committee in 1930, William Paley of CBS produced a chart showing that popular music shows -- at 29 percent -- dominated his program log.)

So if a pop music show was not quite daring programming in December 1934, one featuring a music called swing, by an unknown bandleader named Benny Goodman, was. The three-hour tour de force was called "Let's Dance," and the National Biscuit Co. was the sole sponsor -- itself an innovation because no single advertiser had ever contracted for so large a chunk of weekly time.

Still, Nabisco hedged its musical bets, for in addition to Goodman's swing crew, two "straight" or "sweet" dance orchestras, led by Kel Murray and Xavier Cugat, were hired to round out the Saturday night showcase of popular music.

Since the program originated in New York at 10:30 p.m., the three-hour time differential meant West Coast audiences were hearing "Let's Dance" in prime time. And with the Great Depression on, radio built enormous audiences in those choice hours. Los Angeles pop fans, who seemed always to have a reputation for being avant-garde in their musical tastes, thus provided the obligatory vanguard of support for Goodman's roaring anthems superimposed on the rhythm section's driving beat.

But Benny Goodman had another ally who may have helped his cause as much as the "Let's Dance" radio show. The clarinet-playing maestro's recordings were getting heavy play on Los Angeles' independent stations. (It should be remembered that in early broadcasting, radio that was not live was considered second-rate.) The independents, caring less about such stigma, hopped on the Goodman bandwagon. Al Jarvis in particular stands out. Considered a pioneer disc jockey with his "Make-Believe Ballroom," which sowed the seeds of Top 40 radio, Jarvis was the prime cheerleader in the selling of Benny Goodman.

In addition, Los Angeles newspaper columnists were keeping tabs on the Goodman phenomenon. Wrote one in The News, "I don't see how there could have been any musicians on duty at Los Angeles radio stations last Wednesday night. All seemed to be present at Benny Goodman's opening."

Following the Palomar engagement, the swing publicity mills worked overtime. With Goodman crowned the "King of Swing," the wire services and mass circulation magazines cranked out story after story. A whole new vocabulary ("hepcat," "killer diller," "rug cutter"), every bit as pervasive as that which emerged in the Age of Rock, inundated the land. The momentum generated by the swing fad carried Goodman as a viable entertainer, albeit to an aging coterie of followers, through the next five decades.

Relatively inactive on the musical front these days, Goodman presides over his estate in Stamford, Conn. With the exception of a minor back problem that has nagged him throughout his career, the jazz clarinetist is in good health. In May he participated in a celebration at his alma mater, Hull House, and also accepted an honorary degree from the University of Connecticut at Stamford. He still practices regularly, but has not toured recently with one of the small groups that became his forte after he scrapped his big band many years ago.

Goodman declined a formal offer to appear at this year's Kool Jazz Festival in New York. At a June 25th concert, however, in the middle of the festival's "Tribute to John Hammond," he appeared on the Avery Fisher Hall stage as an unannounced guest. Fronting a quartet for several tunes and a septet for a few more, Goodman was greeted with a rousing welcome akin to the kind he received when he ruled the pop music world as the "King of Swing" -- this despite an audience that included fans of a more contemporary musical persuasion.

The surprise Goodman appearance was a special gesture to Hammond, one of popular music's premier talent scouts, who was stricken with a stroke recently and unable to attend the tribute. It was Hammond who produced Bessie Smith's last records and helped launch the careers of Billie Holiday, Count Basie, Bob Dylan, Bruce Springsteen, Stevie Ray Vaughn -- and Goodman's own first successful band.)

Whether the old euphoria rekindled at Avery Fisher Hall will spur the white-haired Goodman to make more personal appearances remains to be seen. Before the recent New York festival, he was seriously considering some September gigs. Perhaps after that Kool reception, he may even consider opening a 50th anniversary tour in Los Angeles.

After all, pop music entertainers and their fans, like everyone else, know they can't go home again, but they probably have more fun trying.