Fifteen tons of electronic equipment and what do you get? The elaborately staged Mannheim Steamroller Fantasy Tour, which arrives at the Warner Theatre for concerts Thursday, Friday and Saturday night.

It's the mixed-media creation of percussionist and composer Chip Davis, a compact man of 40 with a boyish face and a trimmed auburn beard. At the moment he's seated in a D.C. bar tossing back a few beers, explaining how running his high-end audiophile record label American Gramaphone out of Omaha has it advantages. Omaha appeals to him, he says, and besides, everything about his way of doing things is a bit strange.

To understand just how true that is you have to go back some. Back before Mannheim Steamroller records acquired a relatively small but avid following, before there was a thing called new age music and before Davis' career underwent an implausible but fortunate series of twists. All the way back to the early '70s, when he was just another aspiring, classically trained composer, making a buck writing jingles for an Omaha ad agency.

One commercial for a local bread company called for a simple ditty, the sort of tune a truckermight hum in his sleep. Davis came up with the jingle and copywriter Bill Fries, having failed to find a suitable singer, added his own voice to the spot and called his character C.W. McCall. The commercial went over big. So big, in fact, that soon there wasn't one ad for Old Home Bread but a series of them. They became so popular, Davis says, that television listings in Omaha even noted when the commercials were scheduled to run.

One unlikely event led to another. The next thing Davis knew, he and Fries were out of advertising and fast becoming country music stars. The CB craze helped their best-known tune, "Convoy," sell 7 million copies, enough to convince someone in Hollywood that a film based on the song, starring Kris Kristofferson, might not be such a bad idea.

"Funny thing is," says Davis, settling back in his chair, "I never wanted to live in Nebraska and I never wanted to write country music." This from someone who was voted Country Music Writer of the Year in 1976.

Now country music seems the furthest thing from Davis' mind and work. In 1978, he quit touring with Fries (who, not to be outdone, also switched careers to become mayor of a small town in Colorado). Davis had been working on his own music while in the jingle business, but now he was free to put Mannheim Steamroller into high gear.

Mannheim Steamroller is more a concept than a group. The name derives from the 18th-century Mannheim School in Europe, whose proponents placed a strong emphasis on using the full dynamic range in music. But Davis' original idea really grew from his college-days infatuation with art rock. He had always found the synthesis of classical music and rock fascinating, so he concocted the name Mannheim Steamroller and released the first of a series of recordings called Fresh Aire. That was 13 years and several million records ago.

"Fresh Aire to me was the first song I wrote on the first album," says Davis, whose initial four releases had seasonal themes. "But I was writing more things in the Fresh Aire genre -- which is an eclectic mixture of baroque, classical rock, Renaissance -- it can be everything. The sixth album works its way into French impressionism ... so when I got requests to do more 'Fresh Aire' music I kept the name for the entire series."

"I didn't need Fresh Aire to make a living so we always put the money back into the company," he recalls. "All of a sudden when the McCall stuff started grinding down, I looked around and realized how big {Fresh Aire} had become. It was big enough to support doing it full time by then."

When he ran out of seasons, Davis turned to more heady topics that required extensive research -- Greek mythology and Johann Kepler's 17th-century treatise on space travel. Davis recorded those scores with the London Symphony and Cambridge Singers, but his biggest seller so far is "The Mannheim Steamroller Christmas," a Grammy nominee in 1983.

His trademark is his instrumentation as much as anything -- a distinctive mixture of electronic and acoustic instruments, including several ancient re-creations handcrafted by his father. From the outset, all the albums were pressed on high-quality vinyl and lavishly packaged. And because a lot of stereo salespeople began using them to demonstrate speakers, more and more audiophiles began ordering the albums to take home.

Later, American Gramaphone got an additional boost by a couple of unrelated industry developments: the advent of CDs and the growing awareness and exposure of new age music.

"We were on the edge of the CD technology," Davis declares. "The thing that made us a natural was that everyone knew us as an audiophile label. So when we made the jump to CD we were already there technically. In fact, we had some of the first digital equipment in the States."

As for new age music, Davis isn't comfortable with the label, but he doesn't deny that interest in soothing, atmospheric music has helped his cause. "At least now people know where to find our records in a store," he says. "There was a time when you might find us anywhere -- under classical or Mantovani, because our name starts with an 'M,' or art rock."

His latest album is likely to broaden his audience even more. He's teamed up with guitarist, composer and comedy writer Mason Williams on "Classical Gas," an album devoted entirely to Williams' music.

Since they were fans of each other's work, the collaboration went smoothly. "The original 'Classical Gas' was really the forerunner of baroque rock," Davis enthuses. "I loved baroque rock in college and occasionally a piece like that would come out ... and give me impetus to start writing in that style."

Rearranging the tune was fun but a bit daunting, he admits. "In some of my work I've done orchestrations of Debussy and things like that, and I really feel the weight of the composer. If you can enhance it or somehow heighten the experience, that's the biggest role you'd ever dare play."

According to Davis, the concerts next weekend will feature a sophisticated light, sound and video show built around an array of instruments, computers, four-channel audio equipment and special effects. Since the shows will mark Steamroller's Washington debut, Davis is not sure what kind of turnout to expect, but he's not taking any chances. "We have a direct-mail list that indicates that there are 3,000 fans within a 50-mile radius," he explains. "I wrote them all a personal letter.