Modal Counterpoint in Two Parts
Two Part Motets
In the Renaissance the Motet was a vocal composition based on a sacred text. The rhythm of the text and natural accents dictated where notes were placed in the music. The liturgy of the church was often used, and the Kyrie, Sanctus, Benedictus, and Agnus Dei are short texts. They were commonly written in a melismatic style, with many notes per syllable. The Gloria and Credo, with many more words, were frequently more syllabic, with one note per syllable. Another technique that composers adopted was repeating short phrases, which provided more words.
Structurally, the phrases in the text became melodic phrases that ended with internal cadences. The style was imitative, and a new phrase after each cadence set up a point of imitation between the voices. A common technique was invertible counterpoint between the voices. This means the two parts can be interchanged, with the upper part becoming the lower part and vice versa. This is usually found with an octave between the parts. Upon inversion the imperfect consonances remain consonances, but when the perfect 5th becomes a perfect 4th, a problematic dissonance may occur.
Two Part Canzonets
A Canzonet was a vocal composition based on a secular text. These texts often had more words than the sacred ones used for the Motets, so the music was a bit less melismatic. Canzonets featured shorter phrases and frequent internal cadences of varied types, not just the ornamented Clausula Vera. The modal style of writing was similar, but more progressive harmonic treatments gave the music the impression of modern functional harmony.
Two Part Instrumental Music
Stylistically, the music for instruments written in the 16th century was very similar to the vocal music. The controlled use of consonance and dissonance, the melodic principles, the cadences, and the practice of imitation in polyphony were shared.
There were, however, some subtle differences. There was more interplay between shorter motives and canonic imitation. Frequent sequences were used in the instrumental music, as was a wider range in the parts. Rapid figures and repeated notes were more idiomatic. Most of the music was written flexibly for any available combination of instruments.
Materials
de Lassus: Fulgebunt justi sicut lilium (PDF)
Morley: I go before, my darling (PDF)
Gastoldi: Musica a due voci, No. 9 (PDF)
de Lassus: Oculus non vidit (PDF)