Now, a dozen years after Miles Davis launched the jazz-rock movement, that movement is a dim, diluted version of Davis' original vision. Last week Davis reappeared on state and record for the first time in five years to prove he's regained that vision. Last night at the Merriweather Post Pavilion, two of Davis' ablest alumni -- Joe Zawinul and Wayne Shorter -- proved they never lost the vision. Zawinul and Shorter led Weather Report through an exhilarating performance that married the musical sophistication of jazz to the emotional urgency of rock.

As good as Weather Report is in the studio, their records sometimes sound overly calculated and overly dominated by Zawinul. There were no such problems last night as the playing was full of democratic, open-ended improvising. Shorter stood out much more than he does on record and reminded everyone that he is still one of jazz's most creative saxophonists. Jaco Pastorius, who has revolutionized the electric bass as Jimi Hendrix once did the electric guitar, quoted knowingly from Hendrix during his long bass solo. Trap drummer Peter Erskine provided aggressive swing, and guest percussionist Bobby Thompson provided Caribbean accents.

More important than their virtuosity, though, was Weather Report's emotional eloquence. For more than two hours the compositions by Zawinul, Shorter and Pastorius were filled with sadness, weariness, struggle, triumph and celebration. Pastorius has a way of bending his bass notes to get almost vocal tones, and Zawinul can create total ambiences out of his synthesizers. Yet more than one sone was shaped by Shorter's tenor saxophone, which would begin with melancholy meditations only to slowly gather strength till it reached a climactic, cathartic cry of joy.