An exerpt of the "Gloria" of Josquin's Missa pange lingua. The term "pervasive imitation" describes both the compositional technique and the musical texture. Each phrase of the borrowed melody is used as the basis of a new canonic exposition, and each new exposition marks a new section of the composition.
#Pervasive def free#
The resulting texture was one in which canonic expositions alternated with free polyphony. Moreover, fragments of the melody were allowed to migrate, even in non-canonic sections, through all the voices. The melody no longer remained confined to the tenor but was presented in turn in canon in each voice. Rather than disguise the melody, Josquin treated each phrase of the melody as the subject of imitation (canon, as in "Row, Row, Row Your Boat"). In the music of Josquin, the cantus firmus is retained in its original form. With the notes of the borrowed melody protracted and the borrowed melody itself embedded in a highly complex polyphonic texture, it became very difficult to recognize. Other faster-moving lines were composed around the borrowed melody. In addition, the line was placed in a lower part, first the lowest voice and later the tenor. To make the borrowed melody, or cantus firmus, viable as the superstructure of a musical movement, composers held each note significantly longer than in the original rendering. Later composers sometimes adapted melodies from other sources such as popular song, yet they continued to treat the song melody as if it were a chant. Church law forbade changes to the notes of the melody or the text. In the case of improvised organum, the composers of Notre Dame, and Machaut and the mass composers of the Ars nova, the melody was a chant drawn from the musical liturgy. From the organum of the tenth century to Josquin, composers used a preexisting melody as the basic of their musical compositions. Josquin Desprez (c1440-1521) was an important figure in the promotion of a radical new treatment of the cantus firmus. Theoretical Advances: Josquin and Pervasive Imitation