You couldn't call the newly reopened Apollo Theatre a restoration, exactly. The fact is, the old place on Harlem's 125th Street never looked quite so grand, not in its prewar prime when everyone from Duke Ellington to Pigmeat Markham was on the marquee, not in the '50s and '60s when Otis Redding, James Brown and Gladys Knight were entering its Amateur Night contests. However glittering the talent on stage, the theater -- a one-time burlesque house -- looked shabby as far back as anyone can remember, which, in emcee Ralph Cooper's case, is more than 50 years.

"In its heyday it was far from glamorous, very worn-out, hardly a dash of paint on it," Cooper recalls as a makeup man in black leather pants and one rhinestone earring daubs foundation onto his cheeks. This Wednesday evening, like most Wednesdays since 1935, Cooper will shepherd almost 30 acts through Amateur Night. "Now we got these new seats, carpeting, gorgeous chandeliers. It never looked like this. This is unbelievable. People that knew it walk in and say, 'What happened?' "

Other things have changed at the Apollo as its $10.5 million renovation continues. It's about to acquire a 24-track recording studio, which should prompt a raft of "Live at the Apollo" albums, and a television studio on top of the landmark building, garnished with a satellite dish. During its traditional summer hiatus in July and August it will become acquainted, for the first time, with such newfangled notions as air conditioning and an elevator. All this after a decade of uncertainty: it closed in 1976, reopened only to close again in 1979, was bought in 1981 by a group including former Manhattan borough president Percy Sutton and a company called Inner City Broadcasting, reopened in 1983, closed for renovations in 1984 and reopened last month.

What hasn't changed, in any fundamental way, is Amateur Night. Chandeliers or no, it's still Cooper bringing acts on stage ("talent galore, and we got more") and venerable hoofer Howard (Sandman) Sims shooing them off with a cap pistol when they bomb. Wednesdays draw a still endless stream of kids from church choirs in Brooklyn and the Bronx, waiting to wail like George Benson or moan like Bessie Smith, and, lining up for tickets an hour and a half before showtime, an audience that overflows the 1,550 seats, an audience charitably described as participatory. Amateur Night at the Apollo is the original Gong Show.

"It's the same raucous, loud, vociferous audience that loves you if they think you're doing great and lets you know just as vociferously if they think you need a little more rehearsal," says Cooper, knotting a bright pink tie. "Sometimes they overdo it, get a little unfair to people." Meaning that a disapproving audience will drown out a singer's second chorus with boos and catcalls, prompting a loud siren and the unwelcome appearance of Sandman Sims.

Cooper prefers to see this as a useful critique. Take the example of singer Luther Vandross, who confessed during a recent Motown special taped at the Apollo that he'd blown Amateur Night four times. "Luther was run off this stage not once but four times," Cooper confirms. "They did him good -- they made a star out of him. When he came back, he was okay."

The name and shame of Luther Vandross are echoing through the dressing rooms tonight, a kind of talisman. If they didn't know when they arrived, by showtime the contestants have learned from their colleagues that the SRO crowd can turn mean, that the siren can sound in mid-arpeggio. It's slightly comforting to learn that one can endure such humiliation and still become a star.

"If Luther Vandross came four times, I'll be back five," vows Jackie Alston, 25, of Queens, one of two singers to perform "Good Morning Heartache." She's upstairs chatting with the other women. The men wait in a carpeted room below the stage.

"I said I'd never come," puts in one of the singers who's seen Amateur Night before. "I felt so sorry for the people. It was frightening. If the audience paid $5 and you aren't good, you gotta sneak out the back door."

"Well, I have to think positive," replies Cassandra Perez, 17, from the Bronx. She's wearing a glittery black dress and gold flakes around her eyes, preparatory to singing "Endless Love." "I mean, I don't want to sound conceited, but I'm confident about myself."

Downstairs, the men banter with the same bravado. Five comedians in their twenties who'd arrived for yesterday's Amateur Night auditions had suddenly found themselves transformed into an improvisational group, courtesy of Ralph Cooper. They will each get two minutes at the mike.

"He said, unless you're Eddie Murphy or Richard Pryor you're gonna bomb," Garrett Fortner grumbles. (Cooper can be a bit heavy-handed; he put JWP, a trio from Richmond, on tonight's lineup but renamed it the Foxy Ladies.) But the five comics have decided to make the best of it: Marlowe Smith, who has the unenviable honor of going first; Angel Nieves; Jeff Price; Tony Sparks, who came from Arkansas a few months ago to become a star; and Fortner.

"You know, Richard Pryor came in fourth," Price assures them.

"And Luther Vandross, he never won."

"Yeah, the Jackson Five got booed." It doesn't matter whether any of this is true. It helps.

The show begins with a drum roll, some shimmying by the Rainbow Dancers, applause for Cooper, and the first boos, for the opening act, a slick group called the Unity Band. Sandman Sims, who sits behind a curtain stage right with a canvas bag stuffed with props and his siren at the ready, holds off. Fortunately, most of the contestants are out of earshot and don't know that Cooper is already trying to calm the crowd. "They came to entertain, now," he chides. "They came to try."

It could be worse; in fact, it used to be. One of the balconies was known, 30 years ago when Sims first became "the executioner," as "the buzzard roost." "They threw anything available," Sims remembers. "Ink bottles. Soda bottles. Beer bottles. One guy threw a chair. It landed in the aisle. We cut that out.

"I'm their protector, not the executioner. Because that audience can get really hostile. We've had contestants panic. One jumped off the stage and ran. One started fighting. Or they just stand there. I can tell when they're in trouble. There's a diplomacy about it. I try to take as much attention away from them" -- not difficult when Sims is wearing baggy pants and a top hat or long johns or a diaper, shaking cowbells or a tambourine -- "as I can. If I don't go out and get them, the audience'll give me hell. They wait outside the theater and say, 'What are you doin', Sandman? You asleep back there?' "

Sandman, who won Amateur Night 25 times as a tap dancer (he claims he inspired the four-win limit now in effect) and went on to vaudeville glory, has cakewalked offstage with some of the now-highest-priced talent in show business including, yes, Luther Vandross. "The first time, he didn't know what was happening. Then he got the feeling of it and he came back and did it. He did a job. And he got a standing ovation, maybe for his courage."

Sandman sits out a soloist, a 20-year-old recently arrived from Detroit who instinctively realizes that this is a crowd that doesn't appreciate the slow build: You grab them fast or you're waltzing off with the Sandman. Marisa Turner, though introduced by Cooper as "a little lady I want you to know," is a big woman with a big voice. She gets cheers by the time she's reached the second syllable of "Somewhere . . ." and whoops before she gets to ". . . lullaby." When she walks offstage to sustained applause, people backstage are telling her how great she was. "The opportunity to perform here at the Apollo is the greatest thing I've ever experienced," she says quietly. "I've always heard about it."

Geanette Coleman from the Bronx, who follows, is less lucky. Midway through a mild but perfectly decent rendition of "The Way We Were," a siren wails; the band starts to blare and Sims runs in shooting. Coleman takes his arm and struts off, smiling broadly, telling sympathizers backstage that she's not taking it personally.

For 2 1/2 hours Cooper and Sims will shuffle singers and dancers on and off. Apollo "amateurs" are a practiced group, armed with falsetto swoops and throaty growls, polished in the use of microphones and outstretched arms, and in almost every case professional enough to win amateur contests anywhere else.

The crowd is slow to respond to the five comics -- "There were so many people in my family we had to sleep in shifts," says Marlowe Smith. "Boooo," says the crowd -- but they warm up to Tony Sparks ("I'm from the South; you can tell by the rope burns around my neck") and are cheering by the time Jeff Price unleashes his fat joke. "We killed 'em," Fortner exalts backstage. A chubby young man in a maroon suit practically stops the show with "The Greatest Love of All." "I thought he was going to take up a collection there for a minute," Cooper remarks. Downstairs, everyone is amazed to learn that Kenton Rogers, who more commonly sings with the Canaan Baptist Church in Paterson, N.J., is 16 years old. Jackie Alston is one of the eight performers -- the Sandman keeps track -- who get the siren. But the so-called Foxy Ladies from Richmond -- Wanda Harris, Joyce Cox and Parthenia Wallace -- are a hit.

At the end Ralph Cooper and his son, producer Ralph Cooper II, select the winners by calling everyone out on stage, holding a hand over each performer's head and gauging the applause. Cooper Sr. resists all suggestions that applause meters might be more accurate. It takes 10 minutes, but he eventually winnows the field. First place -- $200 and a return engagement as an invited though poorly paid guest -- goes to the 16-year-old from Paterson. Marisa Turner takes second; the Richmond trio is third; singer Tracie Antoinette, 17, from the Bronx, wins the fourth prize of $50. They pose for pictures as the audience files out, sated.

When Sarah Vaughn won Amateur Night (she was 18 and sang "Body and Soul"), first prize was only $10, but there were compensations. "Billy Eckstine came in and saw the show -- he was singing with Earl (Fatha) Hines' band -- and in two weeks I was in show business," Vaughn remembers.

How much this evening still launches stars is an unanswered question as the resurrected Apollo metamorphoses into a video and audio production house and Harlem tries to pick its way between gentrification and decay. Amateur Night, myths aside, was never an automatic passport to fame.

Stephanie Mills, for instance, was an 11-year-old from Brooklyn when she won two weeks straight, singing a Jackson Five number and then a Stevie Wonder tune. "When you're a kid, you don't know fear," she says now. "If I'd had to get up there as an adult, I'd be scared to death." Winning led to her first professional booking, opening at the Apollo for the Isley Brothers, but it wasn't until five years later that she starred in Broadway in "The Wiz."

And some performers will probably succeed without the Apollo. JWP, a k a the Foxy Ladies, has toured the world singing backup for Grover Washington Jr. and is headed for a Las Vegas engagement next month. The Ladies were already pros when, inspired by the Motown special, they flew up to audition for Amateur Night and walked away with $75 split three ways.

But the Apollo kept its legendary aura even as it crumbled and closed; now, winning still seems like a benediction. "We're part of history," one of the comics says, and he isn't joking.

"They can play anywhere else they want to," says Sandman Sims, who turns into a normal-looking man in a windbreaker on 125th Street. "If they've never played the Apollo before, they're amateurs to us."