The acoustic guitar, with its long lineage of stringed descendants, is an ancient instrument that has delighted the mind and charmed the senses for centuries. Recently, however, its subtle voicings and wry twangings have seemed somehow out of place, and the instrument has been eclipsed by the electric guitar, whose power and savagery more accurately reflect the clank and roar of modern life.

On Saturday and Sunday, the Cellar Door presented two musicians whose different approaches to the acoustic guitar demonstrate the qualities that make the instrument relevant to this or any other age.

Headlining the show was John Fahey, a guitarist whose homespun playing is combined with a modern mentality. Fahey blends elements of folk, blues and bluegrass with starkly dissonant phrases that revitalize the older styles while softening and humanizing the new. Playing a steel-string guitar, he presented several extended songs that leap from one style to the next while never forsaking a sense of musical coherence. When he switched to an old acoustic Hawaiian guitar, his version of "Steamboat Going 'Round the Bend" evoked images of an earlier, lazier age that exists now only in song and verse.

In contrast to Fahey's style were the dark chordings and intellectual music of Bill Conners, a jazz musician whose electric playing has been notable for its restraint and taste. His work with the nylon-stringed classical guitar was somewhat less directed and his playing, for all its technical proficiency, was tentative and lacked the maturity of his electric work. His acoustic playing, however, did present new and potentially rewarding creative possibilities. He is a guitarist whose work bears watching.