Balloons and confetti rained down upon the stage. A dozen white doves flew from the top balcony across the top of the audience's heads and magically disappeared into a little white box at the front of the stage. Fireworks went off and, if I'm not mistaken, I heard a cannon roar.
In any other field, a golden anniversary would probably not warrant the hoopla that Michael Smuin conceived for the company he co-directs with Lew Christensen. But 50 years is a long time in American ballet history - East or West. And the San Francisco Ballet is, in fact, the first to reach that landmark in the country - thus this grand finale celebrating its 50th anniversary, held at the War Memorial Opera House, where the troupe performs through May.
As the anniversary program made clear through old movie clips and montages of photographs as well as live performance, the history of the California troupe is not only long but illustrious.
Generally one tends to think of ballet as a phenomenon of the Atlantic seaboard, an extension of European culture. But the San Francisco Ballet experience tells of prominent artists who found themselves in California and stayed there to nurture their craft.
The real core of West Coast ballet is the Christensen brothers. American-born and, like all Americans involved in the arts in the 1920s and '30s, well-seasoned on the vaudeville circuit, the three Christensens eventually buckled down to work in their home turf. In 1938 Willam Christensen became director of the San Francisco Ballet. Among his many ballets were some of the first full-length classics produced by an American company - ''Swan Lake,'' ''Coppelia,'' and ''The Nutcracker.'' Although it was Balanchine's production for the New York City Ballet in 1954 that would make ''The Nutcracker'' a national craze, Willam did it first in 1944, with much information and advice provided by Balanchine.
Willam was leading the company when Harold Christensen took charge of the school in 1942. Lew Christensen, meanwhile, was back East, working with Balanchine - and in the process becoming the first genuine American danseur noble. In 1952 Lew replaced Willam as director of the San Francisco Ballet, when Willam began to sow yet more ballet seeds in Salt Lake City, establishing a school and company that grew into today's Ballet West.
During the '40s and '50s ballet was virtually a Christensen enterprise in the West. They weren't the only teachers by a long shot, but it was they who pioneered ballet as a professional, performance-oriented course of study. A youngster could go to San Francisco knowing that he might eventually be able to work there. Thanks to the Christensens, the West was not a mere stepping-stone to the East.
Today Lew's presence and that of his mentor, George Balanchine, are still deeply felt in the company's repertory. Indeed, one of the most beautiful moments in the retrospective anniversary program was a snippet from Balanchine's ''Serenade''; and one of the funniest was a film clip of Lew as a marvelously deadpan Prince in Balanchine's parody of ''Swan Lake'' for a 1940 movie called ''I Was an Adventuress.''
The Balanchine, or Eastern, link will undoubtedly remain, but the San Francisco Ballet is a decidedly Western operation. ''A home-grown product is the image we want to present,'' says Dr. Richard LeBlond Jr., president of the San Francisco Ballet Association. ''Home grown'' refers not only to dancers but choreographers as well. LeBlond says that Smuin, the company's current chief choreographer as well as co-director, ''is obviously in a white heat of creativity right now and is an absolute nut on developing other choreographers from the company.'' In the last few years the company has produced some 80 new ballets. That's a record in itself.
Another Western factor that LeBlond wants to see reflected on stage is ethnic diversity. He'd ''love to discover the Arthur Mitchell of the West,'' he says, referring to the black dancer who founded the Dance Theater of Harlem, and he has a fantasy of kids of all colors and national origins ''walking into the school off the street, getting hooked on ballet just because the school is right there in their neighborhood.''
The school LeBlond refers to is not the converted garage that's been miraculously functioning as company headquarters for the last 30 years. He's talking about an $11.5 million plant under construction in the city's downtown Civic Center, just across the street from the opera house.
More than the fireworks of the anniversary program, it's the sound of drills coming from the site of the new school that really heralds the future. For the first time the dancers won't have to commute the long distance between rehearsals at the present school and performances at the opera house. Administrators won't have to keep their files in an old oven and other makeshift crannies. LeBlond won't have to plow through Lew Christensen's office (an old tool shed) to get to his desk.
The new building, set for occupancy in late 1983, has eight full-size studios. Remove a sliding wall between two of them, and you get a space as large as the opera-house stage and pit combined. This greatly smooths the transfer of ballets from rehearsal to performance. The new building also has a variety of other facilities that would all seem to be requisites for any large-scale organization but are still luxury items for most dance groups. For example, a library, study areas for students with homework to do, and a room in which to view videotapes of ballets will be included. It's all within grasp of the San Francisco Ballet - even the additional $2 million needed to see the building through to completion. As chief money raiser, LeBlond takes pride in the fact that he moves the company and school into a mortgage-free building. It gives the company the freedom to go about its artistic business - developing new dancers and choreographers.
''We're the old-timers of dance out here, which is a nice place to be,'' LeBlond reflects. But when asked what his dream wish for the company is, he says it's to discover the choreographers of the next generation.