When he was a vibrantly youthful, handsome and blond 17, Gower Champion and his sister, Jeanne, formed the vastly popular ballroom dance team Gower and Jeanne. In the late 1930s they formed a vastly popular act in vaudeville and the land's poshest nightclubs. In Washington their stand was the Mayflower on Connecticut Avenue. It was a glamorous room, musically noisy, nicotine-sodded and immensely popular with the capital's bon ton.

So it was fitting that his widow, Carla and his two sons decided that producer David Merrick's elaborate "42nd Street" would go on with the planned opening night party in the Waldorf Astoria Starlight Roof.

Gower Champion, visibly aged and known to be desperately ill, had died around 1 p.m. but to protect the production's cast and audience Mrs. Champion and her sons told producer David Merrick: "Go on with the show. Go on with the party. Gower wanted it that way."

And it was indeed a grand party, more muted, of course, than it would have been but entirely fitting to the dancer who became an admired choreographer and successful director of musical comedies, among them "Bye, Bye Birdie," "Carnival" and "Hello, Dolly!"

The band played music from all of them and around the dance floor were such celebrated folk as Ethel Merman, who had once done her year of "Hello, Dolly!" under Champion's direction; Joseph Papp, whose "A Chorus Line" has been a fascinating bridge between "Dolly" and "42nd Street," and Joshua Logan, whose great productions have included "South Pacific" and "Mr. Roberts."

Logan and his wife, Nedda Harrigan, daughter of the famed leader of comedy's Harrigan and Hart team discussed the evening's exceptional dramatic events: "It's the sort of show we've always thought they did in those days, but they really didn't do them," said Nedda Harrigan. "Merrick has made it the way it was meant to be, always up and always singing along. This is the sort of show everyone has been trying to do and isn't it wonderful that Gower did it?"

Josh Logan caught the point of the unexpectedly dramatic evening: "This great extravaganza with its marvelous pacing and dancing will be Gower's lasting monument. I think it will run for years."

By intermission time at the theater the press was trying to get backstage to learn reactions of the company to news of Champion's death, which had begun to seep through press channels.

Only four or five people of the production's inner core knew of Champion's death, among them company manager Louise M. Byer, who, unknown to the publicity man, Fred Nathan, of Champion's passing. Nathan's assignment was to be in the front of the historic 80-year-old Winter Garden Theater to be sure that the critics were all in place and ready to react without extraneous emotion to the extravaganza they were about to review. Because the hour was relatively early (curtain time was early) they had stayed in their seats for the exceptional audience response to the curtain calls.

Merrick's appearance on stage must be one of the most historic, emotional moments of this legendary theater.

Everyone in the house recognized Merrick and waited as he seemed to take his time. All anticipated one of Merrick's long-savored wisecracks. He took a long time, almost too long. Then his voice broke and he said "Grower Champion died this afternoon." This was a shock almost silently received, yet not exactly a surprise to some in the audience and to the huge cast, the largest to appear in years on a Broadway stage.

At the party, late to arrive, Lee Roy Reams, who scored the hit of his career in a strong dancing role which had gotten fatter and fatter under Champion's directions, said:

"I was shocked, shaken. Then I realized what a magnificant finale it was to a great career. Here that crowded house had stood to applaud and to cheer for endless curtain calls. It was the result of months and months and months of work, refining, cutting, sharpening and so that applause was all for Gower and his great staging. No one knew what had happened, including us.What a magnificent, thrilling way to end such an influential career. Yes, he would have wanted this party, have been fully at home with it and enjoyed even our stunned shocking atmosphere."

Most shaken and yet quick to recover was the young leading lady, Wanda Richert, who had gone from several "A Chorus Line" parts to the role of the girl who saves the show. Richert had broken up completly as she was led from stage center after Merrick's announcement but 20 minutes later from her dressing room and after receiving the comfort of Mrs. Champion and Merrick, she came out fourth-rightly: "Gower would have wanted the party just like in the show. Let's go."

While the large brassy band on the Starlight Roof played excerpts from the most noted Champion and David Merrick musicals, word filtered through the party that the first TV reviews were raves.

Star Tammy Grimes, who had had her own private party with her family at Sardi's, arrived and jaunty Jerry Orbach, whose face at Merrick's announcement at stage center was one of pale shocked disbelief, caught the spirit of this strangely haunted party, a complex sense of gratitude, sorrow, shock and triumph.

It was finally a sense of triumph which dominated the dancing, shouting, memorializing group. One of Merrick's managers thought to call one of Champion's earliest discoveries, Carol Channing. Her husband, Charles Lowe, between the acts of the new, touring "Sugar Babies" in St. Louis, was advised "Don't tell Carol till after the show is over."

That had been the feeling among the few who knew the news during the '42nd Street's now historic opening night. "Don't tell anyone. Let the house and the cast enjoy the show for what it is, for what Gower and David meant it to be, fun, dance and sheer escapism." "That was the way to do it," said those hardened into Broadway's tough yet sentimental professionalism. This was the zenith, indeed a cliche in excelsis of professional musical comedy. Let Gower be remembered in just this way.