Monteverde in his day dared to introduce the unprepared seventh of the dominant triad; but, in boldness he was not alone. In fact, the development of polyphony from the wholly unembellished and quite faulty chord progressions of early medi?val music, has been but a series of innovations at first condemned, then suffered, and then adopted. The earliest polyphonic writers founded their music wholly on the ecclesiastical scales derived from the Greek modes, and approved by Ambrose and Gregory. With the single exception of the Ionic scale, identical with our scale of C major, these scales were defective chiefly in one essential, to wit: in place of the modern sharped seventh, they contained the flatted seventh. This error precluded the possibility of the characterizing major third of the dominant chord in both the major and the minor. Then again, the sounding of the flatted seventh, which in modern tonality indicates modulation to the subdominant key, suggested to the old contrapuntists a triad now deemed wholly foreign to the tonic. The resulting vagueness found remedy where one should least expect it, for, in their melodies, the popular writers of both song and dance were led instinctively to sharp the seventh, and otherwise reconstruct the six defective ecclesiastical scales.