Like an idea whose time has come, David Grisman's "new acoustic music" (or "dawg music," as he calls it) is spreading in ever widening circles. Grisman took bluegrass' standard acoustic instruments (mandolin, fiddle, guitar and bass) and freed them to play jazz improvisations, classical arrangements, Third World rhythms or anything else that popped into his head. This opened up new possibilities to musicians who clung to the resonant tone and intimate quality of acoustic stringed instruments.

Grisman hired the best of these musicians for his band; many of them (Darol Anger, Mike Marshall, Tony Rice, Todd Philips and Mark O'Connor) have gone on to form their own bands and to spread the gospel to a wider circle. The following albums represent the field's founder, apostles and converts.

The David Grisman Quartet: "Acousticity" (Z Acoustic ZA 001). Mandolinist Grisman comes up with several new and welcome wrinkles on his now familiar sound. First, he boasts two new members -- fiddler Jim Buchanan and guitarist Jon Sholle -- who reinforce the quartet's bluegrass and jazz roots, respectively, with superb picking. Secondly, he applies his "dawgology" methods to new genres on the quite successful "Brazilian Breeze" and "Dawgalypso."

Most radically, Grisman has recorded with a drummer for the first time. L.A. session legend Hal Blaine adds an extra percussive push to tunes like "Acousticity" (an all-acoustic rock 'n' roll song based on a James Brown riff) and "Ricochet" (a high-speed chase of a catchy theme) without ever obscuring the picking. The album's best song, though, is bassist Rob Wasserman's elegantly harmonic "Blue Sky Bop." The new players and arrangements should surprise Grisman's old fans, and the drum-pushed melodies should bring him brand-new admirers.

Darol Anger, David Balakrishnan and Matt Glaser: "Jazz Violin Celebration" (Kaleidoscope F-22). Fiddlers Anger and Marshall and bassist Wasserman (all Grisman alumni) are joined by fiddlers Balakrishnan and Glaser and guitarist Mike Wollenberg for a live record from a San Francisco concert last November.

They tackle jazz standards by Thelonious Monk, Horace Silver and Louis Armstrong as well as similar originals with three or four fiddles. The loose, freewheeling playing never achieves the focused power of Grisman's tight arrangements, but the energetic spirits and contagious comradeship offer other rewards.

Pete Kennedy: "Sunburst" (Rosewood 001) and "Rhythm Ranch" (Rosewood 002). Kennedy, a local guitarist, has been largely overlooked here, even though he can hold his own with Danny Gatton and Roy Buchanan. On these two self-released cassettes (P.O Box 10104, Fairfax, Va. 22030), Kennedy showcases himself persuasively on acoustic guitar.

"Sunburst" is firmly in the "new acoustic" vein, with five pastoral solo pieces and two lively collaborations with Anger, Marshall and Skyline bassist Larry Cohen. The solo pieces present Kennedy as a consummate craftsman and atmospheric composer, but the combo pieces boast firmer melodic themes that are passed among the musicians with accelerating momentum.

If "Sunburst" is more substantial, "Rhythm Ranch" is more fun. Joined by such local luminaries as fiddler Mike Stein, banjoist Cathy Fink and accordionist Marcie Marxer, Kennedy presents a sampler of traditional acoustic song forms: bluegrass, gospel, Cajun, Irish, Dixieland, gypsy and swing. His lead vocals are surprisingly effective, and the solos by Kennedy, Stein and Fink are vigorous in each genre. Highlights include the sassy swing vocal harmonies on "10 Cats Down" and the greased lightning solos on Django Reinhardt's "Mystery Pacific."

Various Artists: "Great Acoustics" (Philo PH-1101). The current acoustic music revival was celebrated by recording these excerpts from the fourth annual Acoustic Music Festival at Harvard. The set is balanced between singer-songwriter folkies like Dave Mallett, Nanci Griffith and Greg Brown and "new acoustic" instrumentalists like Anger, Marshall, Pierre Bensusan and the members of Skyline.

The album illustrates how the "new acoustic music" has both lowered the barriers and raised the standards for all acoustic genres. As a result, some of the folkie confessionals seem musically undernourished while by contrast Bensusan's guitar solo seems self-revelatory. Anger steals the show as his fiddle flashes through a challenging duet with Marshall and two numbers with the progressive bluegrass quintet Skyline.