Within the world of progressive bluegrass, newgrass and a host of other purity-spoiling fusions, the traditional bluegrass sound of the Johnson Mountain Boys hits you like a refreshing breeze sweeping right off Johnson Mountain.

Well, that's not totally honest.

"There isn't a Johnson Mountain," says Dudley Connell, laughing. "It's just a name.

"My dad had a band in high school called the Johnson Boys and we just took it from that. People still do come up, though, and say to us, 'Hey, I know where that mountain is,' " says Dudley, a guitarist and lead singer for the Montgomery County quintet.

The name is about the closest thing to a false note this group has struck in more than six years playing together. With five critically acclaimed albums to their credit and a reputation on the club and festival circuit as one of the most exciting bands working, the Johnson Mountain Boys repeatedly have been hailed as saviors of traditional bluegrass.

"I'm flattered by that," says Connell. "When we started doing hard-core bluegrass, there weren't a whole lot of bands playing that sound. It seemed it was mostly taboo except for the older big names like Bill Monroe, Ralph Stanley and Lester Flatt. When we began playing clubs it wasn't easy because progressive bluegrass had such a foothold here. People would come to a show wanting to hear songs like 'Rocky Top,' 'Fox on the Run' or 'Rider,' and we just didn't do those type of things."

One of the reasons that the torch of traditionalism has passed to the Johnson Mountain Boys (they'll perform with Peter Rowan and the Nashville Bluegrass Band at Fairfax High School on Saturday in a fundraiser for WAMU) is that as traditional acts go, they are a young bunch of musicians. Unlike most bluegrass musicians of their generation, they never showed much interest in rearranging Beatles or Bob Dylan songs. The group's latest record, "We'll Still Sing On," is all gospel and Connell continues to write originals full of the same high and lonesome sounds and themes as bluegrass classics.

"My folks played traditional country music," he explains, "so I developed a love for it early in life. That's all I ever wanted to play, and it's a miracle that five guys from the same area were all into the same thing. We all love the old hard-core stuff."

Connell moved to Gaithersburg from West Virginia and by 1979 had formed the core of the band. Fiddler Eddie Stubbs and bassist Larry Robbins came over from the Bluegrass Image, and banjoist Richard Underwood came from Buzz Busby's band. The final addition was mandolinist Dave McLaughin, who was originally in the group in 1978, left and then rejoined in 1981. From the start, part of the band's appeal was its ability to offer more than just a recitation of classic bluegrass.

"We used to play regularly at a little club in Rockville called the Gallery," Connell recalls. "Most of the people who came to see us week after week weren't even bluegrass fans, but they responded to us because we gave them a good show."

From their white Stetson hats and perfectly tailored suits to the sheer emotional drive and musical verve of their performances, the Johnson Mountain Boys have established themselves as dynamic showmen. As early as 1981, at a festival in Lavonia, Ga., the group's vibrant classicism was setting off sparks in the bluegrass world.

"It was a big deal for us," Connell remembers. "Being from the D.C. area, we were considered northerners down there. This was our first festival appearance in the South, and it was important for us to get acceptance. We performed on Saturday night and the crowd just wouldn't let us go. We got five or six encores. It was an emotional milestone for us."

Since then the group has won a number of bluegrass awards and polls, and recently played the Grand Ole Opry. In 1984, the band spent five weeks playing in six African nations as part of a USIA-sponsored tour.

"What was great about it," Connell explains, "was that we got to play for the people, not Americans. The black audiences there had no preconceived notions about bluegrass. Here it has all those southern hillbilly connotations. The music got to speak for itself and the people just went wild, yelling and all. They were totally enthusiastic."

That tour confirmed a notion held by the Johnson Mountain Boys and many other popular bluegrass acts. If the music could get more exposure, it could be more commercially successful. "I think that's true," Connell agrees. "We would like to stretch our wings and get our music in front of some different audiences. We'd like to open for some country acts and see if they would go for us."