Susan Lucci of the soap opera "All My Children" recently replaced Bernadette Peters for three weeks in "Annie Get Your Gun." Kathie Lee Gifford of "Regis and Kathie Lee" is going on for Carol Burnett on Tuesday nights through Feb. 15 in "Putting It Together." Robert Urich of "Spenser: For Hire" has just completed a three-month stint in "Chicago" and may return this summer. And tonight, Jack Wagner of "Melrose Place" and "General Hospital" is stepping into the title roles in "Jekyll and Hyde."
     Not one of these television stars - along with numerous others who preceded them - had appeared on Broadway before. None had the classic up-through-the-ranks training that has marked theatrical careers since the days of Ruby Keeler. None had reputations as distinguished actors on film. Some even had to take vocal lessons to pull off their parts.

Changing channels: Jack Wagner, best known for his television roles, joins "Jekyll and Hyde" on Tuesday.

     But in an age when Broadway, more than ever, has become dominated by megamusicals and revivals dependent in part on ticket sales to tourists, this did not seem to matter. Producers are increasingly turning away from Broadway's traditional talent repositories and toward the ultimate mass-market medium - television - to help fill seats and the demanding lead roles previously saved for theater's most accomplished veterans.
     "It is like a consumer product and you're trying to build market share," said Scott Zeiger, the president of SFX Theatrical, which produced "Jekyll and Hyde." "A star gives you that competitive edge."
     While television stars have been trickling into Broadway shows over the last 20 years, this season and last's are notable for their sheer number. Last season brought Tony Danza of "Taxi" in "The Iceman Cometh," Polly Draper of "Thirtysomething" in "Closer," Scott Wolf of "Party of Five" in "Side Man" (as well as the film actors Christian Slater and Andrew McCarthy) and Wayne Knight of "Seinfeld" and now "Third Rock From the Sun" in "Art."
     Perhaps tellingly, producers do not seem confident enough in these stars to have them originate their Broadway roles. Rather, the stars are generally brought in as replacements in a rather brazen attempt to boost ticket sales for a show that is already up and running.
     While movie stars are almost guaranteed to draw crowds on Broadway, television stars are not as sure a bet, some producers say. "TV stars are more transient," said Emanuel Azenberg, who produced "Iceman" last year. "Their stardom has a finite life."
     With years of experience on Broadway - including a Tony Award for her performance in "Song and Dance" and a Tony nomination for "Sunday in the Park With George" - Ms. Peters, who reclaimed the role of Annie Oakley last week, is considered the queen of Broadway musical theater. By contrast, Ms. Lucci has spent the last 30 years on "All My Children" and, although she gave a strong audition for "Annie Get Your Gun," she had to work with a vocal coach while preparing to fill Ms. Peters's shoes.
     Ms. Gifford is stepping in for Ms. Burnett, who has had a long career performing on Broadway in productions like "Once Upon a Mattress" (1959) and "Moon Over Buffalo" (1995) as well as displaying her musical theater talent on her long-running variety show. Ms. Gifford hosts a morning talk show, although she is a cabaret singer who has performed in cruise ship commercials and on her Christmas specials.
     James Naughton, who originated the role Mr. Urich filled, first appeared on Broadway in 1977 and has since won Tony Awards for his performances in "Chicago" and "City of Angels."
     Though he went to drama school and studied acting with Stella Adler, Mr. Wagner has spent his career on "General Hospital" and "Melrose Place." Previous actors who have played Jekyll and Hyde include Robert Cuccioli - the original - and Robert Evan, both of whom paid their dues in regional theater.
     In the past some Broadway neophytes have faced lukewarm receptions. In reviewing Donny Osmond in "Little Johnny Jones" in 1983, Frank Rich wrote in The New York Times: "The young Mr. Osmond is as yet a limited performer whose dancing is more like prancing and whose expressions range from a mild pout to a broad grin (with few gradations in between). But he is sincere and does know how to sing."
     Several members of the latest group of imported stars have fared better. In Newsday Linda Winer grudgingly commended Ms. Gifford's Broadway debut. "Of all the casting stunts in recent Broadway infamy, the hiring of Kathie Lee Gifford for a Stephen Sondheim revue would seem to catapult the merely cynical into the legends of the outright contemptible," she wrote.
     "In fact - and Howard Stern is going to hate this," she concluded, "Gifford is professional, conscientious and actually a little touching."
     For their part, the Broadway newcomers say they have gotten far more out of the experience than what for them is a comparatively modest paycheck and publicity. "I trained like a marathoner for this," Ms. Gifford said. "I went in like a sponge and said, 'Fill me up.' I'm the virgin here."
     This virgin experience stands in stark contrast to a time when the Great White Way seemed reserved for the seasoned masters and symbolized the ultimate prize in legitimate theater: a reward for years of voice, acting and dance classes, for toiling in regional playhouses, touring companies and summer stock productions.
     Sure enough, in his review of Ms. Lucci in The New York Post, Clive Barnes found her greenness problematic. "What she lacked, apart from experience, was much real presence," he wrote, "that sense of stage charisma that all legendary roles in Broadway musicals absolutely demand.
     "For the moment at least," Mr. Barnes added, "she shouldn't give up her day job."
     As more stars infiltrate theater, the call for craft has been less insistent, some observers say. For one thing, with most actors using microphones on stage - to the chagrin of sound purists - the art of great vocal projection is no longer essential.
     Broadway producers defend television stars as formidable talents, fast learners and, in today's market, financial necessities. "Having a television star on Broadway is a wonderful hedge on your bet," Mr. Zeiger said. It gives you press attention, it gives you something to market and it helps you cut through all the other clutter that's out there."

A worker touches up the new sign outside the Plymouth Theater.

     Producers also insist they only cast the stars who are up to the task. "I think it's great that he's a television star and that adds whatever it adds," Frank Wildhorn, the composer of "Jekyll and Hyde," said of Mr. Wagner. "But the reason Jack is coming in is, he's a great singer."
     As far back as 1959, David Merrick presented Jackie Gleason in "Take Me Along." Since then Broadway has been visited by stars like Sid Caesar in "Little Me" (1962), Gilda Radner in "Lunch Hour" (1980) and David and Shaun Cassidy in "Blood Brothers" (1993).
     Fran and Barry Weissler have made a regular practice of putting television stars in Broadway shows. Their 1994 revival of "Grease," for example, included everyone from Maureen McCormick of "The Brady Bunch" to Mackenzie Phillips of "One Day at a Time" to Ricky Paull Goldin of "Another World."
     "We used everybody who could walk," Ms. Weissler said.
     Some have come with considerable stage experience, like Tom Wopat, now in "Annie Get Your Gun," who may be best known for television's "Dukes of Hazzard," but made his Broadway debut as long ago as 1978 in "I Love My Wife." Bebe Neuwirth, acclaimed for her role in "Chicago," also comes from a solid theater background although more people know her from "Cheers." familiar from "Cheers,"
     Mr. Wildhorn said that television stars can draw a new audience that Broadway needs. "Somebody once told me there are more people who watch a successful television show over the course of a season than have ever seen theater in the history of the world," he said. "You're expanding your audience, you're trying to build a nontraditional audience. And I think that's a healthy thing to constantly try to do."
     It is in large part because of television as well as movies, theater veterans say, that Broadway can no longer compete in producing star power of its own, as it did in the days of Ethel Merman, Alfred Drake or Carol Channing.
     As a result, these veterans say, even stage actors who have repeatedly received critical acclaim, including Audra McDonald, Kathleen Chalfant, Brian Stokes Mitchell and Cherry Jones, have not become nationally known. And much of the most accomplished progeny of New York theater - Nathan Lane, Sam Waterston, Kevin Kline, Meryl Streep - have long left Broadway for Hollywood, though they occasionally return.
     Where actors return is often to Off Broadway. Last season brought Calista Flockhart of "Ally McBeal" and Lisa Gay Hamilton of "The Practice," both of whom began in theater.
     Appearing on Broadway gives stars an aura of seriousness and legitimacy, even nobility, in light of the big salaries they are sacrificing.
     Mr. Wagner said that taking on "Jekyll and Hyde" was far from altruistic. "I'm doing this completely for me," he said. "You get a little lazy. I realized I needed something to really pump me up."
     Added Ms. Lucci, who last year finally won an Emmy Award for her longtime portrayal of Erica Kane on "All My Children": "I just love the medium. I loved being onstage."
     Ms. Weissler said Ms. Lucci and Mr. Urich had to audition for their roles. When Frank Gifford auditioned for the role that went to Mr. Urich, he did not even get a call back. "He couldn't do it," Ms. Weissler said. "He couldn't sing and he can't act."
     Ms. Weissler said Ms. Lucci gave a strong audition, but needed vocal training and became a dedicated pupil. "This is a woman who really killed herself," Ms. Weissler said. "We knew people would roll their eyes, but she proved herself to us."
     John McDaniel, the supervising music director of "Annie Get Your Gun" who is also the musical director for "The Rosie O'Donnell Show," said, "I think people were surprised. Audiences stood up every single show."
     Ms. Gifford said she didn't mind that she had been enlisted as much for her marketing potential as for her mastery of Sondheim's lyrics. In fact, she said she had recently written a song about this very reality:
     You really shouldn't take it so personally.
     To them you're not a person, but a personality.
     And you SELL.