Vorspiel, advised, aimed, aimed at, alternative, arbitrary, autonomous, avant-propos, breakthrough, calculated, chosen, conative, concert overture, conscious, considered, contemplated, curtain raiser, deliberate, deliberated, descant, designed, discretional, discretionary, disjunctive, dramatic overture, elected, elective, envisaged, envisioned, exordium, foreword, free, free will, front matter, frontispiece, gratuitous, independent, innovation, intended, intentional, introduction, knowing, leap, meant, meditated, nonmandatory, of design, offered, operatic overture, optional, overture, planned, postulate, preamble, preface, prefix, prefixture, preliminary, prelude, premeditated, premise, presupposition, proem, proffered, projected, prolegomena, prolegomenon, prolepsis, prologue, proposed, protasis, purposed, purposeful, purposive, self-acting, self-active, self-determined, self-determining, spontaneous, studied, teleological, unasked, unbesought, unbidden, uncalled-for, uncoerced, uncompelled, unconstrained, unforced, uninfluenced, uninvited, unpressured, unprompted, unrequested, unrequired, unsolicited, unsought, vamp, verse, volitional, volunteer, willful, willing, witting