Legendary editor Lewis Lapham writes recently of a dream about Charles Mingus so compelling he recalls it clearly 50 years later. Lapham and Mingus agree to exchange address books -- in effect, trading identities -- yet just as they're about to switch, Lapham pulls his back. Mingus jokes, "You don't mean to tell me you're having that much fun with yours." Lapham was ashamed that the dream revealed he neither had "Baudelaire's courage to face down the fear of the unknown" nor to imagine "the signature change from white to black," or overcome his "mortal fear of being poor." Since jazz musicians like Lester Young created the concept of cool -- cool as a mode of Afro Zen -- Lapham's dream from the 1960s lies on its original knife-edge, where a rebel's courage could still help to imagine and create social equality.