The transition from organum to discant was effected about the year 1100. There was for a time no thought of the invention of the component melodies. Not only the _cantus firmus_ (the principal theme), but also the counterpoint (the melodic “running mate”), was borrowed, the second factor being frequently a folk-tune altered to fit the chant melody, according to the simple laws of euphony then admitted. In respect to the words the discant may be divided into two classes: the words might be the same in both parts; or one voice would sing the text of the office of the Church, and the other the words of the secular song from which the accompanying tune was taken. In the twelfth century the monkish musicians, stirred to bolder flights by the satisfactory results of their two-part discant, essayed three parts, with results at first childishly awkward, but with growing ease and smoothness. Free invention of the accompanying parts took the place of the custom of borrowing the entire melodic framework, for while two borrowed themes might fit each other, it was practically impossible to find three that would do so without almost complete alteration. As a scientific method of writing developed, with the combination of parallel and contrary motion, the term discant gave way to counterpoint (Lat. _punctus contra punctum_). But there was never any thought of inventing the _cantus firmus_; this was invariably taken from a ritual book or a popular tune, and the whole art of composition consisted in fabricating melodic figures that would unite with it in an agreeable synthesis. These contrapuntal devices, at first simple and often harsh, under the inevitable law of evolution became more free and mellifluous at the same time that they became more complex. The primitive discant was one note against one note; later the accompanying part was allowed to sing several notes against one of the _cantus firmus_. Another early form consisted of notes interrupted by rests. In the twelfth century such progress had been made that thirds and sixths were abundantly admitted, dissonant intervals were made to resolve upon consonances, consecutive fifths were avoided, passing notes and embellishments were used in the accompanying voices, and the beginnings of double counterpoint and imitation appeared. Little advance was made in the thirteenth century; music was still chiefly a matter of scholastic theory, a mechanical handicraft. Considerable dexterity had been attained in the handling of three simultaneous, independent parts. Contrary and parallel motion alternating for variety’s sake, contrast of consonance and dissonance, a system of notation by which time values as well as differences of pitch could be indicated, together with a recognition of the importance of rhythm as an ingredient in musical effect,—all this foreshadowed the time when the material of tonal art would be plastic in the composer’s hand, and he would be able to mould it into forms of