He would put in a full day's practice on both drums and piano in his formative years. Member of the Charles Lloyd Quartet alongside longtime collaborator Keith Jarrett (he's now in Jarrett's trio, 30 years after their Lloyd days). The first Special Edition LP was a Big Deal in its day - part of a "Cultural Revolution" of the avant-garde in which Jack was "Our Mole at ECM"; he was later the drummer for the Ornette Coleman/Pat Metheny summit Song X. A voluminous discography.