It makes perfect sense for the group led by mandolin master David Grisman to open this weekend’s show by Bela Fleck’s Fleck-Tones. With the style Grisman calls “dawg music”–an ingenious and infectious concoction of jazz and bluegrass (that other “indigenous” American musical idiom)–his music preceded Fleck’s by more than a decade. Fleck has surrounded his banjo with heavy electronics in the rhythm section to arrive at his own all-but-inimitable sound; Grisman, on the other hand, has remained relentlessly acoustic, depending on ace bluegrass guitar pickers and occasional woodwind contributions to add variety and depth to his compositions and recordings. He also avoids the traditional trap-drum sounds that anchor most jazz ensembles, and this helps give his bands their light and cloudless quality–but no more so than the reedy timbre of unelectrified guitar, the sighing swing of violin, and the constant tremolo Grisman himself must use to sustain notes on the mandolin. (That tremolo–the busy, short-stroke bursts of sound–supplies a great deal of the band’s propulsion. It works with the bass and guitar to create a steady pulse from their mosaic of rhythmic bits and pieces.) But as with bluegrass jams, light doesn’t have to mean empty, and Grisman’s furious virtuosity offers plenty of quiet excitement. This string-band instrumentation tends to wear a bit thin in the long run, but throughout his career, Grisman has worked wonders in retaining variety and complexity in his music: his most recent CD, Dawganova (Acoustic Disc), a fusion of dawg music and Latin and Brazilian beats, is a fine case in point. And with the lakeside zephyrs weaving in and out of his breezy textures, Grisman promises the perfect summer-night entertainment. Tuesday and Wednesday, 8 PM, Skyline Stage, Navy Pier, 600 E. Grand; 559-1212 or 595-7437. NEIL TESSER

Art accompanying story in printed newspaper (not available in this archive): photo/Jay Blakesberg.