The guitar may not be all things to all people, but it's probably all things to Pat Metheny. And Metheny, an exceptionally deft and broad-minded jazz guitarist, seemed in his Saturday appearance at the Warner Theatre to be trying to be all guitarists to all styles.

Metheny is a master of lyrical improvisation, expressive and assured. He has both balance and jump-off curiosity. Amid his most elaborate variations, the melody rings. He's so good that he can be almost unobtrusive, obscured by his own music.

Metheny and his group are somewhat less successful when they stretch to the other extremes. The paradox of all "perverse" arts is that they require a kind of absolutism--they are traditional techniques turned inside out. Free-form jazz and time-signature travel require absolute precision, but there were crucial passages in Metheny's adaptations of Ornette Coleman's free-form sax that were merely muddy.

Metheny gave nearly equal time to Lyle Mays, keyboardist and sometime collaborator, who has a disconcerting tendency to get wound up along an improvisation and then find he has to wheel around; and to Brazilian percussionist Nana Vasconcelous, who knows exactly where Metheny is going and plays in and out at will.