THEY STARTED out 10 years ago as a suburban basement band, pickers and friends coming together for a weekly game in which songs and instruments were dealt out instead of cards.One was already a legend in bluegrass, one a doctor, one a cartographer, one a commercial artist, one a mathematician.John Duffey, John Starling, Tom Gray, Mike Auldridge and Ben Eldridge never really intended to move much farther than the living room, prompting another musician to name them. . . the Seldom Scene.

Now, they're at the top, one of the best-known bluegrass bands in the world, winners of so many awards they've stopped counting.

The Seldom Scene made its mark with instrumental virtuosity and an electric repertoire that ranges from Bill Monroe to Bob Dylan to Carter Stanley to Eric Clapton. It also features gorgeous, impeccable harmonies, voices blending sweetly in an urban rainbow of sound that borders on folk. It's a thoroughly modern sound that retains the music's traditional roots, and with it the Seldom Scene immensely broadened the audience for bluegrass.

"A lot of people have come to hear them, and if you told them they were listening to 'bluegrass,' they wouldn't like it," laughs Gary Oelze, owner of the Birchmere, American's premier bluegrass club. The Seldom Scene has worked there every Thurdsay for four years, after six years at the now-defunct Red Fox in Bethesda. "I've seen their show 100,000 times and they're always full of energy. Everybody seems to know they enjoy what they're doing. That's the big secret of it."

Every week, Oelze gets calls from around the country from soon-to-be visitors checking to see if the Scene is still there; maybe they' re hoping Linda Ronstadt or Emmylou Harris will stop by to sing (as they used to before they became famous); maybe they're hopting to see Bill Monroe, John Hartford or the other great pickers who gravitate to the Birchmere when the Scene is there. For whatever reason, the club is always packed. "There might not even have been a Birchmere without the Seldom Scene," Oelze insists. "They kept me in business the weeks and months that nobody else came."

There's even the ultimate Seldom Scene fan, a Japanese employe of Nippon Electric in Argentina. This man's work takes him from Japan to Argentina every three months, and "he routes himself through Washington to see the Seldom Scene," an incredulous Oelze says. Once during the summer festival season, this fan landed at Friendship Airport, took a cab to Gettysburg and caught the Scene's set . . . with the meter running and the cab poised for a return trip. All that for a band that got together for "the fun of it."

By 1969, the fun had apparently stopped for mandolinst John Duffey. In 1957, he, charlie Waller and Bill Emerson had formed the Country Gentlemen, making Duffey a key figure in the two most influential bands in the genre and earning him the sobriquet, "father of modern bluegrass." "I don't mind that," he says proudly.

Duffey doesn't sound or look much different than during his 12-year stay with that seminal group. He still sports a flattop (now graying) and muscular arms bulging from under short-sleeved shirts; he looks like a bowler, and in fact, he bowls every Wednesday night. His lusty tenor is probably higher than his bowling average. "It's a one-in-a-million voice," dobroist Mike Auldridge says.

What Duffey brought to the Gentlemen, and eventually to the Seldom Scene, was a desire to outgrow the rigid framework of traditional bluegrass, particularly the "high, lonesome" vocal sound, the fiery (but predictable) instrumental work and the lack of fresh material. He introduced jazy licks that were soon emulated by a host of younger pickers; the vocals became, less strained; and suddenly people stopped being afraid of bluegrass. "Twenty years ago bluegrass was like pornography," Duffey once said. "It was sold under the counter. Now it's okay for a U.S. senator [Robert C. Byrd] to play it on 'Hee Haw;' it's okay for people to like it."

In 1969, tired of playing too hard and traveling too many miles for too little money or recognition, Duffey quit. When he was invited to pick at Ben Eldridge's house, he didn't even own a mandolin anymore. The folks he met there were not very well known; Starling was an ear, nose and throat intern who had never played in a band before; Auldridge and Eldridge had been playing locally with Cliff Waldron's New Shades of Grass; the bass player was Len Holsclaw, now an Arlington county chief of detectives and manager of the Country Gentlemen.

"We were all real intimidated by Duffey in those days," the mild-mannered Auldridge laughs now. "But the first time we sang together, it was obvious the blend was something special . . . we weren't really 'progressive,' but broad-minded, more so than most bluegrass bands in that we tried a lot of different kinds of music."

Oddly enough, the band's first public appearance was a failure; The upper Northwest nightclub they played at insisted on having the television on louder than the band during a Monday night Redskins game. The Scene quit, moved down the road to the Red Fox; from then on, they played to full -- and receptive -- houses. In all the time he has managed the band's business affairis, Duffey has never has to make a call to get a job.

The band's nine albums have featured blues, rock, jazz, swing, country, gospel . . . and of course, a lot of classic bluegrass. Bluegrass purists were put off by the band's acoustic but driving versions of rock and jazz tunes, but Duffey was always conscious of the need to reach younger audiences. They were accused of fomenting slick, smooth pop, or worse, taking the roots out of the music. But not to worry: Even Bill Monroe, the ultra-conservative father of bluegrass, sits in with the Secne whenever he's around.

THERE'S AN old adage in bluegrass: "Don't give up your day job."

Being a star in bluegrass is not as rewarding as being an also-ran in most other music fields; the audience is small, the venues limited, the record sales insignificant. Despite the Seldom Scene's success, only Auldridge, Duffey and recent addition Phil Rosenthal make a living at music.

Ben Eldridge, a versatile and vastly underrated banjo player, is principal mathematician at Arlington's Tetra Tech, a technical engineering firm working with the Navy on underwater acoustic research. Bassist Tom Gray, who is considered the best in bluegrass, is a cartographer for National Geographic; when he replaced Holsclaw, he'd been out of music for seven years after a stint with the Country Gentlemen in the '60s. He'd given up his day job when he was with the Gentlemen, but the bills soon outweighed the bookings, and unnacceptable mismatch for a family man.

Until 1977, Auldridge was a fulltime commercial artist at The Washington Star, despite being recognized as probably the finest dobro player in the world. He's appeared on more than 80 albums, backing such people as James Taylor, Hank Williams Jr. and good pals Emmylou Harris, Linda Ronstadt and Dolly Parton. Having played on it, Auldridge is one of the few people to have heard the fabled "Trio" album from Harris, Parton and Ronstadt, a project shelved because the artists' record companies couldn't work out a deal. Harris worked the Washington club circuit at the time the Scene was first appearing and would often sit in with them. Ronstadt would also stop by on ocassion; she recorded a song she heard the Scene perform, on her breakthrough "Heart Like a Wheel" album, and has provided backup vocals on three of their albums.

The year 1977 also brought about the only major personnel change in the Scene's 10-year history: John Starling, who had kept his day job as an intern at Walter Reed, left to set up private practice in Alabama. He was replaced by Rosenthal, who came from a Connecticut band called Old Dog that had played the Birchmere several times. He added a youthful appearance and ability to double on guitar, mandolin and banjo.

Starling occassionally comes back and sits in with his old band (as he will tonight at a private anniversary party); except for an excellent album last year and recently completed sessions, he's stayed away from music. "But you always miss something when it was a lot of fun," Starling says wistfully.

WHAT MADE the Seldom Scene so special? "I knew these people were going to be somebody," says Len Holsclaw. "It was ridiculous that someone as great as John Duffey was out of the business. And Mike Auldridge had the earmark of a superstar, he just didn't know then that he was so good. Of course, I was kind of wanting to pick with them. . ."

"They're an excellent band that's done a lot to promote bluegrass in quarters where it wouldn't have been heard or appreciated," says WAMU radio personality Gary Henderson, who used to pick with them. "They did it right," adds Oelze, adding that there is still a lot of jealousy from some of the older, traditional players who "don't feel they've paid their dues 'cause Duffey put together a bunch of super guys that were unheard of and made a lot of money."

"We converted a lot of people who thought they didn't like bluegrass," says Auldridge, "but they liked what we were doing. That was our greatest contribution. It's been a very fast 10 years. I've never felt like it was work, I don't think anybody in the band does. I've had a lot of neat offers from other artists, and I've been tempted to take them. But as long as the Seldom Scene are successful, I'm not going to walk away from them."

REMEMBER that Japanese fan? You can bet he'll be on home assignment next apring when the Seldom Scene makes its first Japanese tour. The band's horizons have expanded considerably in the last year, a combination of Duffey overcoming his fear of flying and the money finally being enough to warrant the travel expenses. "Duffey wouldn't take a job he couldn't drive to," Oelze says. Some tours extended as far north as Canada and as far south as Florida, but it was only recently that the group made it to California. The result: a completely sold-out tour.

Japan's been waiting for Duffey since his days with the Country Gentlemen. The Japanese take bluegrass as seriously as they do jazz. There was even a Japanese copy of Duffey's famous old custom-built mandolin, "The Duck" (so called because of the swooping curved points at each end). He only learned about it when a fan sent him an ad showing the unique shape, a lot of Japanese words and one English word: "Duffey."

They may bave been never seen in Japan, and Seldom Scene in California, but Duffey and company have been plenty heard in Washington.