There was a time when most country music was pretty much the same. Whatever it was called, it generally consisted of a fiddle- banjo-guitar combination. But with the likes of Jimmie Rodgers, the Carter Family and Hank Williams the up-tempo, foot-stompin' variety was replaced by ballads of heartache and pain and tears and trains. It came to be known as country and western; the guitar could stay but those wild-and-woolly fiddle- and-banjo tunes no longer fit in.

Then along came Bill Monroe. He had broken up the country duet act he shared with his brother Charlie and in 1939 formed his own band, called the Bluegrass Boys after his home state of Kentucky. In contrast to the rich baritone style of the day, Monroe's high tenor voice gave the ballads an eerie, mournful wail, the "high lonesome sound" that's the essence of Appalachian soul.

By 1945 Monroe had what many consider the ultimate bluegrass band: himself on high tenor and mandolin, Chubby Wise on fiddle, Lester Flatt playing guitar and singing lead and Earl Scruggs on banjo. Before Scruggs, most popular players strummed the banjo, a method known as clawhammer or frailing; he adapted the technique of fellow North Carolinian Snuffy Jenkins, in which thumb- and finger-picks are used in the "three-finger roll."

By embellishing raw hillbilly music with soulful ballads, precise three- and four-part harmonies, a unique, driving banjo sound and a dazzling fiddler, Monroe had created an exciting new genre. As country and western music became more electric and commercial, bluegrass developed as its acoustical alternative, much truer to the roots of country and mountain music.

Monroe soon had many imitators, among them Buzz Busby. Born Bernarr Busbice in Eros, Louisiana, he played bluegrass up and down the East Coast before settling in Washington in 1954.

The Nation's Capital might have seemed an unlikely spot for country music to blossom, but it had been warmed up by impresario Connie B. Gay, a good 'ol boy from Lizard Lick, North Carolina, who couldn't carry a tune in a bucket but sure could make a cash register sing.

On November 7, 1946, Gay signed on Station WARL with a new program called "Town and Country Time" -- accent on the country. It was the first "hillbilly" show aimed at any major American market, and before long was being rebroadcast by more than 1,800 stations. Gay paid Roy ("Hee Haw") Clark $60.18 a week; promising comers like Johnny Cash and Elvis Presley got a couple of hundred a shot. The late great Patsy Cline knew she had made the big time when Gay paid her $25 a show.

Gay piled success on success until he had network TV shows, live jamborees, train excursions to Nashville, country-music cruises on the Wilson Liner, and dozens of other promotions. He soon made country music so respectable in Washington that in 1948 he sold out Constitution Hall for 27 straight Saturday nights, a record that still stands. Among other things he founded the Country Music Hall of Fame; last year they elected him to it.

Busby and his band, the Bayou Boys, were regularly packing 'em in at such D.C. honkytonks as the Famous Restaurant and the Pine Tavern, long since gone. The band was so popular in 1955 that WRC-TV put them on the air with "The Hayloft Hoedown," broadcast daily during the dinner hour, when all the folks were home.

Not to be outdone, WMAL-TV (now WJLA) put on Jimmy Dean and his Texas Wildcats, hard-core country and western. Pretty soon Washington viewers and listeners could get country almost round the clock. Dean, who had started out with Gay as "The Country Clown," eventually had a monster hit with "Big Bad John" and moved on.

Busby has not been as fortunate. In 1957, while on the way home from a gig in North Beach, Maryland, he was in a car wreck so bad the ambulance driver pronounced him dead. Busby proved him wrong, but spent several months in the hospital.

Meanwhile his band picked up new members and, calling themselves the Country Gentlemen, became Washington's bluegrass sensation. Fellow Louisianan Charlie Waller, who had been the lead singer of the Bayou Boys, was the focal point of the new group.

Busby's career has languished, although last year his brother Wayne made "Buzz Busby: A Pioneer of Traditional Bluegrass" the maiden release of his Gaithersburg record company, called Webco. A second album's on the way. At 48 Busby's voice falters but his mandolin playing is as sharp as ever; bluegrass will always be indebted to him.

The Country Gentlemen have never slowed down since they formed up on July 4, 1957. After 25 years, more than 50 albums and world-wide tours, the band remains a bluegrass supergroup. Although Waller is the only remaining original, the sound and the reputation of the group have endured.

Before the Country Gentlemen virtually all bluegrass was traditional. But Waller, along with John Duffey (mandolin), Tom Gray (bass) and Eddie Adcock (banjo) gave the music a fresh approach which came to be labeled as progressive, or "newgrass."

The band members played their instruments with a jazzy feel, and Waller's voice was strong, deep and distinctive, without the nasal quality of his predecessors. They borrowed heavily from folk and popular tunes of the day rather than the standards about drinking, dying and life on the farm.

By 1960 the Country Gentlemen had firmly established urban bluegrass, and Georgetown was the center of it. From 1960 to 1972 the Gentlemen hung their hats in a noisy, smoky redneck bar on M Street known as the Shamrock (now Winston's). Audiences got more than music: Duffey and Adcock were the original wild and crazy guys, and their antics were refreshing compared to the grim-faced, tight-lipped style of most other bands.

The Country Gentlemen temporarily lost their zest for club dates one night in 1972 when Bill Emerson, who had replaced Adcock on banjo, was shot by "a person unknown" from a passing car as the group left the former Red Fox Inn in Bethesda. The bullet passed through Emerson's right arm; he recovered fully, but then joined the Navy band known as The Country Current. He's still with it.

During that same year the Country Gentlemen were forced to share their title as Washington's best with a new group calling itself The Seldom Scene. John Duffey, who had quit the Country Gentlemen in 1969, was the impetus behind the new group. After a bitter taste of the big time, Duffey dropped out again and opened an instrument repair business in Arlington.

Two years later he was lured into playing with other area musicians at a local "pickin' party." The sound was so good they decided to put a group together.

Duffey persuaded Walt Broderick, owner of the Red Fox Inn, to give the band a try. He gave them Tuesdays, his slowest night; soon there were long lines at the door.

The Seldom Scene took the contemporary, progressive bluegrass invented earlier by the Country Gentlemen farther in the same direction. They were doing songs by folkies like James Taylor, Steve Goodman and John Prine, even more palatable to urban ears.

And Washington's white-collar crowd could identify with these good young boys: Lead singer John Starling was an Army physician; dobro player Mike Auldridge a commercial artist with The Washington Star; bassist Tom Gray a National Geographic cartographer; and banjo player Ben Eldridge a mathematician.

Ten years and nine albums later the Scene is considered by many to be the nation's best bluegrass band. The only change in personnel occurred in 1977 when Starling moved to Alabama to enter private practice. He was replaced by Phil Rosenthal, from Connecticut (yes!)

The Seldom Scene started out "to be our weekly card game," according to Auldridge. Just a night out with the boys to play a little and hoist a few. But it wasn't in the cards. Linda Ronstadt recorded their "Keep Me From Blowin' Away," in 1974, the following year contributed to the band's "Old Train" album, and then sang on their "New Seldom Scene" LP.

For most of the '70s the Red Fox Inn was the focal point for Washington bluegrass. In 1977 a new club, the Birchmere, then located in Arlington, offered to double the Seldom Scene's pay if they would move their act across the Potomac. Torn by loyalty to the Red Fox, the band eventually gave in: The Birchmere was larger, had an excellent sound system, and the management insisted on absolute silence during performances.

Now in even larger quarters in Alexandria, the Birchmere has become a national bluegrass showcase.

While all this was going on, WAMU-FM, the public radio station at American University, began beaming bluegrass seven days a week at 50,000 watts. From one night a week in 1967 and a handful of listeners, the sound has graduated from late-night obscurity to a noon-to-6:30 weekday slot, with an average of 81,500 listeners, according to the most recent Arbitron rating. The station has just added three more hours of bluegrass on Saturdays -- noon to 3 -- and no wonder: During its most recent fund drive, 43 percent of the $153,000 donated by listeners came from bluegrass fans.

The success of the Country Gentlemen and Seldom Scene has led to the formation countless local bands since the early 1970s. To date there are some 50 groups based within 30 miles of Washington. They compete for work in fewer than two dozen clubs, which generally offer the music only once or twice a week.

Because of the noncommercialism of the music, the pay scale for a bluegrass band is a fraction of that earned by rock, disco and country bands. For most musicians it's recreation rather than a vocation. Nor is it a guaranteed money-maker for clubs and restaurants; the music fails in as many places as it is successful.

That may be no bad thing, since it keeps the spirit of the music close to its roots. Some of the best of the bluegrass boys, such as Donnie Bryant of Arlington, feel no need to play for pay.

Bryant left the circuit twenty years ago and joined the Metropolitan Police. From time to time, while rising to captain, he filled in on banjo or guitar when called in as a recording side man or to cover for a sick member of the bands of Monroe, Flatt and Scruggs, Mac Wiseman and others. He just grinned as he turned down the long-term offers that generally followed.

Bryant, whom Wiseman has called "about the best banjo picker that ever was born, except when he's thinking about the guitar," recently retired. He gets no end of invitations, but still plays almost exclusively for friends and for love of the music.

On his backyard patio last Saturday night he casually ran through a repertoire that left one friend near tears, so clean and quick and piercing and delicate is his style.

"Man, how can you play that kind of music and keep it to yourself?" he was asked.

"Well," Bryant said, "I really just learned it for myself.""