NEW YORK -- The first assault came less than a minute after Andrea Holdclaw opened her mouth. Boos rolled like sheets of thunder from the mezzanine, the balcony and the orchestra, rattling crystal chandeliers in the lobby.

The young singer from the District never even flinched. She had waited too long for this moment, honing her showcase tune, "Somewhere Over the Rainbow," to a tense, sweaty perfection.

Draped in an aqua-colored satin gown, she simply clenched her fists and cranked it up a couple of octaves. That did it. Silenced by her overwhelming determination, the crowd of 1,500 at Harlem's Apollo Theatre had switched to cheering by the time she hit the first refrain.

Other performers were not so lucky. On "Amateur Night at the Apollo," the slightest mistake can seal your fate. New York's historic midwife to musical fame, the Apollo's warm spotlight has been fixed on joyful winners for more than five decades. Yet for every Ella Fitzgerald or Michael Jackson, whose victories on Amateur Night here launched them on careers of dazzling glory, dozens of acts drown in jeers.

"These audiences are smart, but they can get nasty," said Sheryl Robinson, an usher, sadly shaking her head as a massive vocalist who called himself Shades of Ebony was hooted from the stage. "You want to make a run at the big time, you got to be ready to take some big-time knocks."

Everything at the Apollo Theatre has always been Big Time. Opened in 1934 as an uptown alternative for black musicians at a time when they were barred from performing at most other venues, the Apollo has played host to nearly every major black vocalist since World War II. But its greatest success from the beginning has been with Amateur Night, that once-a-week marathon where anyone with steel nerves, a voice box or an act can come out and chase a dream.

Ralph Cooper, the salty master of ceremonies for Amateur Night, has been introducing the Wednesday night acts since the year the club opened. Some evenings, he seems more like a lion tamer than a cabaret host. But that is the essence of the Apollo crowd -- one minute throwing roses at an old woman crooning "Inseparable" and the next hooting a weeping teenage tap-dancer out of town.

"I'll never forget the day Billie Holiday first sang here," said Cooper, who has just published a history of his life at the Apollo. "I had heard her all by accident at a little dinner place up the street, and I told her to come on down.

"Well, she was scared witless," he recounted. "The orchestra didn't think she could cut it. They thought I was out of my mind. Billie was so scared we had to push her onto the stage. But from the moment she opened her mouth, she was the greatest star we ever had."

The ornate theater, a centerpiece of commerce and art on Harlem's busiest thoroughfare, 125th Street, has always attracted an odd crowd -- part family, part show-biz, part tourist. These days, no show goes on without at least a dozen or more Japanese visitors. "It's one of the first places on their list," Cooper said. "They even have a version now in Tokyo with a similar kind of Amateur Night."

In his early days as a Harlem drug dealer before he became a Muslim and one of the nation's most arresting orators, Malcolm X could be found there most evenings selling single sticks of marijuana to the country's most famous jazz stars.

These nights, the crowd is still a mix of families with pigtailed girls in Mary Janes, local celebrities and record producers scouting for the next Stevie Wonder. Once broadcast nationwide on radio, the Apollo's evening shows, including Amateur Night segments, now are syndicated weekly for television.

Mike Tyson appeared last Wednesday, taking a bow on stage and hanging out awhile in the "Green Room," the humid, glaringly fluorescent waiting pen beneath the stage for the nervous Smokey Robinson and Dionne Warwick wannabees.

The tension can be unbearable. That night, the audience would select 1990's "Super Dog," the Amateur of the Year. By now, all the contestants had heard that Luther Vandross was hooted from the stage here on four different occasions before he finally found his rhythm. Sarah Vaughan also got off to a shaky start.

"Oh, God," said Charnita Edwards, 21, a vocalist from Baltimore. "If you want to sing, you can't fail here. This is the place to do or die and, right now, I feel like dying."

She did.

With Cooper standing behind her fretting like a worried father, Edwards was chased from the stage by an angry audience that pounced on her the moment it heard the opening bars of "Home," the hit made famous in "The Wiz" by Stephanie Mills, who won here when she was 11.

"Some songs they've heard so many times it doesn't matter what the singer sounds like," one Apollo veteran explained as the seemingly harmonious Edwards slumped off the stage. "If she had picked another tune, she might have won it all."

But those who think that the fast, cold Harlem audiences have no heart should consider Matthew Philips, contestant No. 31. So severely disabled that he can hardly walk, Philips underwent an obvious struggle just to reach the stage.

The crowd grew quiet as he began his deep, searching rendition of "Amazing Grace." For a few seconds, it was not clear which way the verdict would go. Then a gangly teenager wearing unlaced high-tops, a fur coat and three large ropes of gold around his neck slowly made his way to the well in front of the stage.

The bouncers started to move in as he reached into a pocket, but he produced a fistful of U.S. currency in very large denominations. He smiled, threw the money on stage and returned to his seat. Others followed his lead.

"Who says these folks don't love a good act?" Cooper asked, mystified. "Who said it's hard to make it here in Harlem?"