It's a familiar story, Jazz Artist plays serious music for years. The critics love it but the public could care less. Jazz Artist sees the light, hires a slick backup group and thurns to Pop. Records begin to sell, money flows in, fame follows quickly and . . . the music goes down the drain.

Herbie Hancock is just such a fallen jazz artist. His concert last night at Merriweather Post Pavilion, was, in many ways, a renunciation of the innovative musical course which he followed in the late '60s and early '70s.

Forsaking the strident harmonies and intricate melodies of the past, Hancock and his six-piece group stomped their way through a set of vapid, funky material from his recent pop records. Monotonous, incessant beats and shrill guitar chords pounded away, while Hancock flailed at his arsenal of electronic keyboard instruments.

The one notable exception to this motley collection was Hancock's solo performance of his classic, "Maiden Voyage." This early compostion, delicately constructed and impeccably played, provided a revealing and depressing contrast to his latest efforts.

Herbie Hancock is a "sell-out" in the truest sense of the word. And like most artists who are caught in his present situation, Hancock is really short-changing himself.