HOW THEY GOT that soundtrack: Besides playing more than 20 characters in the space of two hours in "How I Got That Story" at Source Theater, actor Mike Judge also supplied the play's "soundtrack," an inventive montage of computer-treated vocal effects that creates a sonic landscape, an audio hallucination of a war-torn country.

"{Director} Steve Hayes and I went over the script together," Judge said, "and we decided where we wanted a specific sound, and how we might achieve it. The playwright, Amlin Gray, suggests some sound effects in the script, but he's very unspecific, so we were really on our own. We wanted to keep it in the spirit of Gray's script -- he wanted to get as far away from specifically Vietnam as possible.

"We had a cup of coffee with Don Zintera, the engineer at Inner Ear Studios in Arlington, and then he just left me and Steve alone in the room to make funny noises for an hour and a half. Then he took my little voice and ran it through the mixing board: he sped it up, slowed it down, multi-tracked and reverbed it, put it through a digital sampler . . . and through the miracle of modern technology we came out with this wild soundtrack."

Judge says letting go of his inhibitions and improvising was difficult at first, but he quickly warmed to playing one-man band. "Being an American male, all the gun battles were fun -- BANG! POW! ZOOM! -- and all that. The cities were fun, too -- I would do this vaguely Oriental gibberish, then walk away from the mike to get the effect of crowds passing by. The helicopter was particularly difficult -- I did the old finger over the lips trick, and over that we recorded the sound of a motor hum." Judge is particularly proud of the affecting Asian lullaby he improvised -- it can be heard at the top and the close of show. "I was amazed at how well that turned out. Actually, I credit the melody to an old Pete Seeger record."

During performances at Source's Main Stage, sound board operator James Malone cues the intricate sound bits to moments of dialogue, lighting changes and movement on stage. "It's very strange, to be onstage, listening to the soundtrack of a show, and realizing it's your own voice," Judge said. A Washington-born actor who works as a bartender at Garrett's Railroad Bar in Georgetown, Judge says he may play the tape at work and "see what happens."

When Geoff Robinson left the Army after 23 years, he decided he wanted to write for the theater. But Robinson was different from many aspiring playwrights -- he decided first to learn about the theater from the inside.

So Robinson began his career in the theater by sweeping the stage. Now he's now stage manager for Source's "How I Got That Story," and director Steve Hayes says he's better at it than many who have done it for years. And since Robinson saw several years of combat in Vietnam, he served as an unofficial "technical advisor" to Hayes and the two actors in the play.

Robinson, who places his age "in the 40s," was involved in theater at military bases, and decided the creative life was for him. He studied "Theater 101" at Prince George's Community College, and someone at the school's Hallam Theater began his dramatic education by saying "OK, we start by sweeping the floors."

"I thought that was just great," Robinson says. "Look, as long as you don't care what your job title is, you can learn something about theater. I moved on to hanging lighting instruments, working sound boards, and then stage managing productions like 'The Good Doctor.' And now here I am downtown, in an honest-to-God theater."

Gung-ho Robinson says his ground-floor, hands-on experience "drastically affects" the way he writes. "You have to be able to imagine what business will be going on onstage; how lights and sound will affect the things you're saying." Robinson's play "Table Talk" will be produced at Hallam Theater this fall, and he is at work on another, called "Drinking From the Well."

Retracing your steps isn't always easy, especially when you first made them 20 years ago. Just ask director/choreographer Bob Fosse, who had to recreate his original choreography for the revival of "Sweet Charity." The touring company of the musical, starring Donna McKechnie, is currently visiting the National Theatre.

"I never learned Labanotation {the standard system of dance notation}, so my notes were full of stick figures and illegible little scrawls," Fosse says. "I dug them out, but they didn't help much. Fortunately we had the movie, which was an adaptation of the original choreography. And we had Gwen Verdon, who did most of the dancing end. She has a much better memory than I do, and even she had trouble remembering everything." Fosse says "Sweet Charity" was also a sweet reunion with Verdon, his first wife, and the original Charity Hope Valentine in the 1966 Broadway production.

"You're always afraid in this business that your work will become dated, but I think 'Charity' has held up pretty well," Fosse says. "I shortened some stuff and tightened it a bit, and I took about 15 minutes out of it, because people's attention spans seem to have gotten shorter." Fosse rehearsed the touring troupe in New York, then followed the show to Toronto to check on "quality control."

"I don't know if I'll go back to Broadway for a long time. It still kind of hurts too much," Fosse says, referring to the critical and financial drubbing he took for his big-budget "Big Deal." Still, Fosse's never been one to sit around and sulk -- he says he is developing a handful of movie projects, including a film version of "Chicago," and is considering Madonna for a lead role. The casting seems more than appropriate, as the superstar singer seems like a character in a Fosse musical, and her Broadway-style stadium concerts owe a substantial debt to the master's dancing style. "That's what she told me," he laughs.

Bulletin Board: Just what we need, another serving of "Greater Tuna." Because of health reasons, songwriter Sammy Cahn has withdrawn his "Words & Music" revue from the Ford's Theater season schedule, and Ford's is bringing back the two-actor tale of Tuna, Texas -- for the third time, already (the show played the Kennedy Center once before that). Playwrights/performers Jaston Williams and Joe Sears will star, October 13-November 8 . . . Howard University has announced its theater season, which includes "Livin' Fat," a comedy by Judi N. Mason, (October 1-10); "Agnes of God" (November 12-21); and "A Streetcar Named Desire" (March 10-19), in the Ira Aldridge Theater (636-7700) . . . Baltimore's Mechanic Theater gets the pre- Broadway run of "that Scottish play," starring Glenda Jackson and Christopher Plummer (January 26-February 21).