Frank Zappa's onstage madness is legendary. His unpredictable combinations of progressive rock, theater and satire have helped to define Dada rock. Saturday night's concert at the University of Maryland's Cole Field House, however, left ambivalent answers to the question of whether there is method in his madness.

Zappa's musical genius was nost apparent on the instrumental, semiimprovisational pieces, "Meek" and "Pound for a Brown," where his compositional blends of classical, rock, electronic and jazz motives were not only expansive but compelling. His satire was most incisive on "Bobby Brown" and "Flakes" - the latter including a satiric impression of Bob Dylan and a general put-down of rock music.

But on other selections the musical montage of classical and rock cliches provided a flimsy backdrop for windy narratives. The satire was neither cohesive nor biting; Zappa tossed off petulant couplets that seemed meaningless as well as Mresome. "Conehead" (an abvious borrowing from "Saturday Night Live"), where Zappa dons a conehead, was amusing to see but otherwise flat.

Included in Zappa's targets for satiric comment were sex, commercials, sex, religion, sex, women's lib, sex . . .

Zappa smacks of good-natured class clowning - sophomoric, harmless. He is a cult in-joke, a class cut-up. On Saturday, sometimes it worked, sometimes it didn't - but maybe that's his charm.