YOU CAN'T judge a band by the company it keeps -- or can you? After listening to "Delinquent Minor" by the local acoustic trio Grazz Matazz, it hardly seems a coincidence that such stellar instrumentalists as Jethro Burns, Mike Auldridge, Bela Fleck and Pete Kennedy would want to contribute to this album. They know a good thing when they hear it.

Take the opening tune: Arlo Guthrie's "Mapleview Rag," while a nifty showcase for Auldridge's Dobro, ultimately leaves no doubt that Grazz Matazz' Al Petteway (on guitar) and Akira Otsuka (on mandolin) can play in the big leagues. Fleet yet expressive, their solos distill the rag's southwestern flavor and fit nicely alongside the playing of fiddler Phil Bloch and banjo player Carl Fanning.

The remaining member of the band -- rhythm guitarist, pianist and vocalit Pat Petteway -- makes her debut on a finger- popping rendition of Dan Hicks' "Walkin' One and Only." Petteway's reedy soprano voice is just right for western swing tunes. But it also has a decidedly plaintive edge at times, especially on the traditional tune "One Morning in May" and the jazz standard "After You've Gone," delightful performances both.

Elsewhere, Pete Kennedy contributes "Sunburst," a sleek flatpicking guitar and mandolin foray into New Acoustic Music, to which Bela Fleck adds a few colorful touches on banjo. Like the title track, it's highly reminiscent of David Grisman's "dawg" music. As for Jethro Burns, his mandolin, in typically unbridled fashion, dances around Mark Shatz' strutting bass lines on "Oh, Lady Be Good," giving this Gershwin classic an infectious glow. The album closes with "Yodel Lady," which displays the Petteways' harmonies and points to a very promising future.

Sharing the stage with Grazz Matazz, Auldridge and Burns this weekend at the Birchmere will be the great banjoist Bill Keith. Strange as it seems, until recently Keith had recorded only one album under his own name. He's regarded as the most innovative and influential banjo technician of the past twenty years, and his approach to expanding the banjo repertoire has had far-reaching effects, paving the way for such as Bela Fleck and Tony Trischka.

"Banjoistics," Keith's new album, brilliantly reasserts his position in acoustic music through an extraordinary, eclectic and imaginative collection of tunes, embracing bluegrass ("Banjo Boy Chimes"), Celtic music ("Morrison's Jig"), jazz ("Mood Indigo"), rock ("Lay Down Sally") and the unusual original composition "Pentachrome."

Throughout, Keith's playing is extremely articulate and appealing -- his open-string melodies, in particular, ring out with uncommon clarity -- and his more chordal jazz essays are delightfully refreshing. The contributions of Keith's longtime collaborator Jim Rooney, fiddler Buddy Spicher and guitarist Eric Weissberg, among others, grace many of the inspired arrangements. GRAZZ MATAZZ -- "Delinquent Minor" (Matrix M018184); BILL KEITH -- "Banjoistics" (Rounder 0148); both appearing Friday at the Birchmere.