Mandolinist David Grisman long ago proved he could push bluegrass instrumentation and technique into the harmonic and rhythmic improvisation of the best jazz. More recently he has molded a combo that plays with a telepathic rapport and a consistent virtuosity seldom achieved by ensembles in any genre. At the Wax Museum Saturday night Grisman's all-acoustic string quartet abandoned the fast unison lines of bluegrass for counterpointed rhythms and harmonies. Darol Anger's fiddle sawed thick, slow drones under Grisman's blistering mandolin picking. Mike Marshall added chop-and-pause rhythm guitar as well as triplet digressions. Bassist Rob Wasserman proved the most jazz-oriented with walking bebop lines and surprising slides. These guys belong in the Kool Jazz Festival.

The opening set was the first public appearance by the First of a Dying Breed. This local sextet featured three super pickers: fiddler Jeff Wisor (formerly with David Bromberg), pedal steel guitarist Danny Pendleton (ex-Emmylou Harris) and electric guitarist Danny Gatton (ex-Robert Gordon). Gatton stole the whole show with guitar solos that cooked the country melodies until they boiled over into astonishing jazz variations. The band's leader, though, was Gene Johnson, who proved a pleasant singer but a weak songwriter. His predictable honky-tonk tunes hardly justified the instrumental extravagance they received.