And few people are as surprised at their existence as the former actors and casting directors and authors who find themselves running them.

Theatre fans looking for original cast albums of recent shows, re-released cast albums of vintage show, or studio albums from theatre stars have come to search out independent labels like Fynsworth Alley, PS Classics, Sh-K-Boom, Original Cast Records, Bayview, First Night, 150 Music, Eagle Vision, 2die4 Music and London's Jay Records. They join the theatre divisions of major labels like RCA Victor, Sony Classical, Columbia Masterworks, Angel, Universal and Decca Broadway.

Those seeking plays, biographies, histories and critical works turn to specialty book publishers like Applause Books, TCG, Limelight Editions, Samuel French and Heinemann.

One such company is truly a mom-and-pop operation. Marisa Smith and her husband, Eric Kraus, run Smith & Kraus, which publishes about 35 books a year, including several monologue books and the works of Beth Henley and John Guare — out of their New Hampshire house. "Our 15-year-old and his buddy maintain the website," says Smith, a former actress and producer. "I've actually called my son at school twice about web stuff."

Smith likes being able to blend her personal and professional spheres, although "the thing about working at home and having two kids is that you never stop working. The hardest part is finding time to actually read." She would be the first to admit that her potential readership is limited, and that's fine by her. "The only way to survive in publishing these days is to find a niche. There may not be that many people in the theatre community, but they all read. And they all buy books."

Terrence Nemeth, vice president of publications at Theatre Communications Group (TCG), is similarly sanguine about the prospects for playwrights. "Right now, authors are in better shape than ever in terms of plays getting published," he says. "There are a lot more opportunities out there."

TCG, which also publishes American Theatre magazine, prides itself on cultivating young playwrights; upcoming releases include works by Richard Maxwell and Karen Hartman. "Our tendency is to develop a writer over a long period of time," Nemeth says. "We published Suzan-Lori Parks six years before she won the Pulitzer." Other noted TCG authors include Tony Kushner and Paula Vogel.

With more than 20 years in the theatre publishing business, Nemeth is a relative old-timer. But he takes a distant second to Hugh Fordin, who created DRG Records back in 1976 after writing a few theatre books and working as David Merrick's casting director.

"It's much more money now and not as much fun," says Fordin, whose recent recordings include the Tony-winning Elaine Stritch: At Liberty, and this season's Flower Drum Song revival. "It's a different business. But we just keep plowing ahead."

Unlike many producers, though, Fordin isn't worried about the Internet putting his company out of business. "I really believe we will always rely on product being sold in stores. I don't feel there will be that much downloading in our little niche of the recording world."

That little niche has grown a bit with the recent advent of such theatre-centric record labels as PS Classics and Sh-K-Boom.

"I didn't have a great scheme or anything like that," says Tommy Krasker, co-founder (with Philip Chaffin) and executive producer of PS Classics. "I just wanted to keep making the music I had loved making."

Krasker got started in producing while he was working as an archivist for the Gershwin estate. His credits include Audra McDonald's three solo albums, songbook albums of works by Jason Robert Brown and Maury Yeston, and the Los Angeles cast album of Michael John LaChiusa's previously unrecorded musical First Lady Suite. Current PS Classics projects include the Roundabout Nine revival — a fitting show for Krasker, whose first job in New York was as rehearsal pianist on the original production.

"It was a huge amount to learn and very daunting," the 43-year-old Krasker says of starting a label. "But it's sort of fun at my age to take on this whole new set of disciplines."

Sh-K-Boom president Kurt Deutsch never really thought about the record business until his wife, Sherie Rene Scott (she's the "Sh," he's the "K" in Sh-K-Boom), was approached about recording an album during her run in Aida. "I looked at the contract," says the former actor, "and I realized that she would never have seen a dime out of it. And I started thinking: 'She's playing to 15,000 people a week. Maybe if we can put a web address in her bio in Playbill, we could record the album ourselves and sell it online. Maybe we can take control of it and make a little money off of it.' "

Sh-K-Boom went on to record Scott's next two shows, The Last Five Years and Debbie Does Dallas, as well as a roster of solo albums by young rock-influenced Broadway performers, including Adam Pascal and Alice Ripley. Soon to be released: the original cast album of this season's short-lived but admired Amour. Deutsch says the label consciously aims to reach "this world of Rent and Tommy and Broadway's next generation" through appearances at New York clubs. "The idea is that Sh-K-Boom would become a production company as well as a record label," he says.

Competition certainly exists among the various labels, but all parties seem to make an effort at civility. Both Krasker and Fordin have produced recordings for other record labels, and Fordin takes a philosophical stance on getting the rights to hot shows: "The way I see it, either they'll get it or I'll get it."

Each company stresses the importance of keeping all its titles in print. Unlike so many best-sellers, which sell by the jillions at first only to find themselves in the remainder bin two years later, theatre titles tend to take the slow-but-steady route. Deutsch calls his recordings "annuities," while Fordin likens the DRG back catalog to "clipping coupons. I never delete an item from my catalog. Never." In fact, Nemeth cites the fact that no TCG title has gone out of print in 16 years as the main reason authors like Eric Bogosian and David Henry Hwang have left other publishers for his company.

For each of these accidental moguls, starting a business has been an unexpected but delightful career path. "This is the scariest thing I've ever done," Deutsch says. "If you do it yourself, you stand a very real chance of failing. But you also stand to reap the rewards.”