ABSTRACT
The layered thirds and sixths in the sonorous principle just suggested must at any given time be resolved strictly into the closest available perfect consonances through half-tone motion in one voice and whole-tone motion in the other. Thus, sonorities tending toward pure motion and pure stasis follow each other, or in other words, stasis and motion were separated from each other vertically. In the fourteenth and fifteenth centuries, a new low voice-the socalled contratenor and afterwards bass-came into being especially in chanson composition. At first it was always only subsequently added ad libitum to already-existing pieces. (In Dunstable this leaping contratenor appears in the motet as well, but as a complement to the tenor cantus firmus [in its role] as director of sonorities [Klangtriiger].) This contratenor, added subsequently to a given piece, cannot, however, be considered to have had from the beginning the same compositional status as the preexisting voices. At first it was not even a true voice, since its individual tones only served to fill out the individual sonorities of the piece at hand. Hence, dynamic melodic motion was not its entitlement, so that it was allowed to have neither the stepwise descent allotted to the tenor nor the rising leading-tone progression identified with the discantus. The propulsive element was retained by the voices of the so-called basic contrapuntal framework [Gerustsatz] , which at first lay mostly-and later always-above [the added contratenor]. This meant, in fact, that the contratenor was allowed to make absolutely no imperfect consonances below the tenor that would have to be resolved, through motion in the contratenor such as is described above and a corresponding motion in the tenor, into the closest available perfect consonances. The only usable consonances for the contratenor [as low voice] were the perfect ones-octave and fifth below the tenor and the unison with it. The major third only became a possibility when it was discovered that one could satisfactorily voice-lead the upper voice with semi tone motion and the lower voice to the octave [below] by leaping down a fifth (Example 2A) instead of voice-leading one of the voices by half-step motion the other by whole-tone motion into a [perfect] fifth (Example 2B).
