"West 57th" is back and still decidedly brilliant. If anything, the version of the CBS News magazine that re-premieres tonight at 8 on Channel 9 is even better than the program was in its first trial outing last summer. It still has flash, but it also has more substance. It is a compelling emotional as well as a compelling pyrotechnical experience.

While NBC News continues to bumble about trying to get a half-decent magazine show in shape, "West 57th" is ready to roll with a hefty backlog of stories, four varyingly charismatic young correspondents and the most innovative approach to television of any news show now on the air.

Fuddy-duddies pounced on "West 57th" when it premiered last summer. It was so entertaining, the pouncers assumed it could not also be journalism. One college professor later theorized that the reason some print critics didn't like the show was because it's the first TV news magazine not to pattern itself on a print model.

"West 57th" dabbles in variations on traditional nonfiction narrative forms that don't always work, but are almost invariably ambitious and fresh. The four pieces on tonight's show could never be mistaken for illustrated magazine articles. They are assembled and edited for people attuned to the textures and rhythms of television.

In the first segment, Meredith Vieira spends time in the impoverished and crime-ridden Uptown section of Chicago -- "the most vicious neighborhood in the entire Chicago area," according to one boozy resident -- and there encounters a remarkable 9-year-old boy named Anthony. Intelligent, articulate and wise beyond his years, Anthony clearly won't be able to realize his potential in this environment, yet he's stuck there. He becomes a moving symbol of societal failure.

About the only common value on the streets Anthony walks is machismo. Everybody tries to intimidate everybody else and, thus, survive. "I hate the way these people act out here," Anthony confides to Vieira in one particularly poignant moment. A former teacher of Anthony's marvels at his scholarship and verbal sophistication, but a repressive current teacher snarls that he has "a problem with his mouth." This teacher becomes a symbol, too, when she says, "I've learned not to worry too much about anything."

The second piece is lighter stuff by far. Correspondent Bob Sirott, still looking startled about finding himself on TV, follows "stand-up comedy's traveling salesman," Jay Leno, as he makes the rounds of America. The Johnny Appleseed of the joke, Leno is a compulsive itinerant who will appear almost anywhere a comedian can be booked.

He's the funster who pulls up to the talk-box at a drive-in McDonald's and asks, "What's the catch of the day?"

Jane Wallace went to Haiti for the third segment and found that though Baby Doc Duvalier is gone, his vicious domestic militia remains, clubbing and bullying and killing. In six or seven minutes, you get a grim portrait of a sickeningly violent society. The United States, it is reported, has supplied the thug-cops with weapons and helped train them.

John Ferrugia's closing segment is profoundly disturbing: American criminals are having easier and easier access to automatic weapons, and a Missouri state trooper, whose partner was killed by one of these superguns, speaks in behalf of pending congressional legislation to inhibit their proliferation.

Unfortunately, Congress defers to the National Rifle Association (NRA) on such issues. It doesn't matter if blood runs red in the streets; the NRA is adamant that the right to own machine guns be protected. An NRA spokesman says people should be as free to collect them as they are to collect "Renoirs." Ferrugia looks ever-so-faintly as though he is going to throw up. It's an understandable reaction.

Whether "West 57th" will suffer the kind of vituperative hysteria that greeted its first outing last year remains to be seen. That Ferrugia and, especially, Vieira and Wallace are first-rate second-generation TV correspondents appears all but irrefutable on the basis of their work so far. In addition, the two women have a camera presence that is commanding.

From the rancor "West 57th" provoked the first time out, you'd think that bright, innovative, exploratory concepts in network television come along every day. The audience, not the press, will have the final verdict on "West 57th" and whether it has managed to position itself on the right wavelength at the right time. My feeling is, wow, has it ever.