Over the last 20 years or so, as the electric guitar has become something of a fixture on the jazz scene, I've established for it an honorary (and imaginary) laurel--a sort of rotating professorship for the hot young guitarist of the moment. This post has been occupied by John Scofield, Bill Frisell, Vernon Reid, and Pat Metheny, but it originated with John Abercrombie, whose lush sound and strikingly romantic concepts have in fact provided the underpinning for many of his successors. Abercrombie first crept into view as a guest artist on the debut LP by Dreams, a pioneer jazz-rock band that featured Billy Cobham and the Brecker Brothers in the late 60s. Since then, he has stretched his concept to include jazz standards in an acoustic-trio setting as well as something just this side of synthesized machine music; in every case, his richly textured sound and sympathetic accompaniment have proved as notable as his seemingly subconscious solos. Musically, Abercrombie is a lover, not a fighter; no matter the tempo, the volume, or the level of electronics, he still caresses the music rather than attacking it, and his most ferocious forays seem born of passion as opposed to anger, honor, or athleticism. He'll appear with bassist Marc Johnson and drummer Peter Erskine, each of whom leads his own band and rates a good deal more than this one sentence. Tonight and Saturday, Joe Segal's Jazz Showcase, Blackstone Hotel, 636 S. Michigan; 427-4300. Sunday, 8 and 10 PM, Crystal Ballroom, Blackstone Hotel, 636 S. Michigan; 427-4300.