John Fahey is not, to the joy of those who love the second of the acoustic guitar, an entertainer. Onstage, he plays only as long as he likes, refuses encores and offers no patter whatsoever while he tunes up between songs. Nor, for that matter, does he make an effort to identify for his audience any of the songs he plays.

But when he gets down to serious picking, Fahey, appearing with banjo player Steven Wade at The Cellar Door through tonight, is quite eloquent. Listening to him play solo acoustic guitar is like watching a musical history of America unfolding before you, so skillful is his blending of native American forms.

Fahey's music is based on the blues, as is almost all contemporary music that is truly American, but it also takes in Appalachian folk songs, traditional hymns, spirituals, gospel music and other elements that antedate the 20th century. He is a walking encyclopedia of unusual guitar tunings, and has a striking way of reworking classic blues motifs so that they fit into the flowing and often haunting melodies of his own devise.

He is, of course, also an excellent slide guitarist, as he showed during last night's brief first set with a stately tune called, "Steamboat Gwine 'Round de Bend." This followed a medley in which Fahey, using an open tuning, showed his mastery of finger picking by playing melody on top of melody at the same time while using his thumb to play a walking base line.

What may be particularly interesting to audience here is Fahey's roots in this area. Although his M.A. in folklore and mythology was earned at UCLA, Fahey grew up in Takoma Park and graduated with a degree in philosophy and religion from American University before setting up Takoma Records, a label he owns and for which he has made over a dozen albums in the last 18 years.