In their attempts to rupture preconceptions of what music is, many composers of the 1960s and 1970s concerned themselves with “concept” as opposed to aesthetics. Artists and musicians of many stripes questioned both how music should be understood as a cultural product and how music should be performed and appreciated as a human activity. Here we spotlight three figures possessed of an experimental turn of mind—renegades, perhaps, but more accurately, searchers. Occasional headline grabbers (not always intentionally so) during those decades, Karlheinz Stockhausen, Pauline Oliveros, and Earle Brown have in common only that they afforded listeners with no conventional points of reference. Stockhausen, somewhat mystically, sought “the sound not yet heard”; Oliveros strove to deemphasize the value conventionally assigned to formal training; Brown emphasized the “creative ambiguity” of all interpretation. Their compositions embody that tendency within modernism that insists upon, indeed creates crisis—as in “crisis of conscience”—as the historically appropriate response to a beleaguered moment in the history of our age. But their conceptualizations of form, notation, and performance also lie at the core of the mobile and open-ended improvisatory music associated with today’s so-called New York downtown scene.