If you happen by either the Renaissance in Washington or the Marriott in Gaithersburg this week, you're likely to find that the halls are alive with the sound of music. From today through Sunday, the Renaissance will host the eighth annual conference of the North American Folk Music and Dance Alliance, while the Marriott will host the fifth annual East Coast Jazz Festival Friday through Sunday.

The Folk Alliance conference brings together 1,500 musicians, agents, record label executives, merchandisers, bookers and so on, all looking to champion a genre that Folk Alliance Executive Director Phyllis Barney concedes is hard to define even as it experiences dramatic growth and revival.

"We deliberately don't have a definition," Barney says. "We have found that if you try to draw a line somewhere, you have left somebody on the other side of the line. Our umbrella is all-inclusive."

In the great folk boom of the late '50s and early '60s, emotional battles were fought over what was or wasn't folk music, most often pitting "traditionalists" against "revivalists." Three decades later, passions have cooled considerably, but there do seem to be a lot of substitutes for the word "folk," whether genre-specific (Cajun, bluegrass, blues) or annoyingly vague (acoustic music, world music).

"One of our biggest challenges is to make the F-word acceptable," Barney notes. "Maybe {the younger generations} attach the word to their parents' generation, so we have to break with the old vision of what the F-word is and present the entire array of incredible music."

For instance, "there are exciting things under the title of world music' that are actually from many culturally based communities," says Barney, who points to a new partnership with the Network of Cultural Centers of Color. "A lot of the new acoustic music' is familiar singer-songwriter ballad-crafting, and there are many young artists capturing people's imaginations, like Dar Williams." Williams recently recorded with and is touring with Joan Baez, an icon of the first folk boom, so the circle will apparently not be broken any time soon.

Like most conferences, the Folk Alliance is a mix of networking opportunities, songwriting workshops, marketing panels, performance-centered sessions and the like (there's also an exhibition hall). The panels reflect both new growth ("Marketing Anglo-Celtic Folk Rock in North America," "Folking Around Cyberspace") and familiar challenges ("New Funding Realities," "Perils and Pitfalls of the Road"). While the conference is not open to the public, walk-up registration is available on a daily or four-day basis. For information, call 202-835-3655.

With the sudden influx of musicians (some 50 percent of conference attendees), there will be a fair number of public shows in and around town, notably a Green Linnet Records showcase of Irish music at the Birchmere tonight, and a Rounder/Philo singer-songwriter showcase at the same location tomorrow.

Tonight at 7:30, the Hard Rock Cafe will host a free ASCAP/Performing Songwriter workshop with panelists Tom Paxton, Michael Johnson and John Gorka and a randomly selected group of 10 performers, followed at 10 p.m. by a showcase of eight artists who have been featured in Performing Songwriter's "Editors Choice" compilation CDs. On Friday, Paxton moves to the Birchmere to record a live album with a little help from such friends as Gorka, Cathy Fink and Marcy Marxer, Robin and Linda Williams, Mike Auldridge, Stuart Duncan and David Buskin.

For a rundown of public events, you can call the Folk Alliance Fringe Activities Hotline at 202-363-3131 (press 8008). The voice you hear, incidentally, belongs to Mary Cliff, longtime host of WETA's "Traditions" program and one of the most forceful and effective advocates this music has ever had. Listen in to Cliff's Saturday program (8 p.m. to 1 a.m.) for a number of live guest performances from the Folk Alliance get-together.

The Folk Alliance will also give out its second annual Lifetime Achievement Awards to Woody Guthrie and Moses Asch of Folkways Records (which is now owned by the Smithsonian). Guthrie's family will receive his award from old pal Pete Seeger (last year's honoree). Asch's son Michael will accept his father's award from Anthony Seeger, director of the Smithsonian/Folkways labels and nephew of Pete, who used to record for Folkways. Folk music is about family, though seldom this literally.

The avowed goal of the Folk Alliance is to foster new audiences as well as new opportunities for those who make and present folk music and dance, and to increase public awareness of the artistic and cultural importance of those culturally diverse genres. There will be some lobbying on Capitol Hill to reinforce the notion that folk arts should remain an integral part of arts funding. Jazz in Gaithersburg

Over at the Gaithersburg Marriott, the operative word is jazz. At the East Coast Jazz Festival, it will be played pretty much nonstop this weekend in a mix of free and paid showcases featuring a variety of local and national talent.

The festival actually kicks off on Thursday with a series of free performances at Walter Johnson High School in Bethesda. After an improvisation workshop led by Marty Nau at 3 p.m. and a showcase by the Walter Johnson High School Jazz Ensemble at 5:30, the day concludes with performances by the Marty Nau Quartet (6 p.m.), the Tom Teasley Quartet (7:15) and the U.S. Army Blues (8:15).

After that, everything shifts to the Marriott, where free workshops and performances (and a Sunday jazz service) can generally be found from morning to midday. Paid concerts will take place Friday, Saturday and Sunday evenings, as well as Saturday and Sunday afternoons (tickets range from $25 to $30 per concert, and a three-day pass is available for $105).

The Friday evening concert features vocalist Lorez Alexandria, saxophonist-composer Frank Foster, the DC/Philly Connection and the Rick Loza Latin Sextet. The Saturday matinee features the Charlie Byrd Trio, Rick Harris and the Little Big Horns Sextet, Jack Clayton and the Stanley Cowell Trio; the evening concert includes the Jon Metzger Quartet, the Clark Terry Quintet, the Donald Dial Septet and Ronnie Wells and Ron Elliston & Friends. Wells and Elliston created and operate the East Coast Jazz Festival, which has made them many friends.

The Sunday afternoon show features the Vaughn Nark Quintet, Byron Morris and Unity, as well as the Kevin Mahogany Quartet. The evening lineup includes Nathan Page and Buster Williams, Houston Person and Etta Jones, the Al Grey Sextet and the Dick Morgan Trio Plus Two. Opens jams will follow each evening program.

Also part of the festival: the Fish Middleton Jazz Scholarship competition, aimed at supporting the educational and artistic needs of emerging artists. The competition is part of the Friday night concert ticket (it runs from 5 to 7:30), with the winners performing at the Saturday matinee. For closure, past winners will perform at the start of the Sunday matinee.

For information, call 301-933-1822.