Josquin and Pervasive Imitation

Theoretical Advances: Josquin and Pervasive Imitation

Josquin Desprez (c1440-1521) was an important figure in the promotion of a radical new treatment of the cantus firmus. From the organum of the tenth century to Josquin, composers used a preexisting melody as the basic of their musical compositions. 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. Church law forbade changes to the notes of the melody or the text. 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.

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. In addition, the line was placed in a lower part, first the lowest voice and later the tenor. Other faster-moving lines were composed around the borrowed melody. 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.

In the music of Josquin, the cantus firmus is retained in its original form. 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"). The melody no longer remained confined to the tenor but was presented in turn in canon in each voice. Moreover, fragments of the melody were allowed to migrate, even in non-canonic sections, through all the voices. The resulting texture was one in which canonic expositions alternated with free polyphony. 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. The term "pervasive imitation" describes both the compositional technique and the musical texture. An exerpt of the "Gloria" of Josquin's Missa pange lingua. The first section is constructed by imitating a single sublect. The second section, given incomplete in the example, is cinstructed siilarly but on a new subject. The third and last section, not given in score, follows the same procedure using yet another subject. The entrances are marked.

Josquin, Kyrie, "Missa pange lingua" (Right click to view score)

Fifteenth-Century Composers and Their Imitative Prototypes

Pervasive imitation was a technique of immense sophistication. In earlier compositions, particularly those of Dufay, the music unfolded in long sections of free polyphony, anchored by a long-note, embedded, unrecognizable cantus firmus. Dufay used canon in his polyphonic compositions of the early fifteenth century, but not in an extensive way. In Dufay's work, short canonic expositions usually appear at the beginning of new sections or phrases, and the subject of each canon is only a few notes in length. The expositions usually involve only two voices. Free polyphonic passages begin in each voice as soon as the fragment of the subject is stated.

Dufay unified his works, however, by the use of motives which he embedded in each voice part. The motives invariably derive from the most recognizable part of the cantus firmus melody, the opening notes. The motives could be used to generate new but related ones by adding notes to the intial motive, inversion, or sequence. In inversion, the basic idea is in a mirror image. If the motive, as in this case, descends stepwise four notes, the inversion ascends stepwise four notes. In sequence, the mitve is given intact but starts on a note other than the original motive. The musical texture then contains the cantus firmus superstructure in the tenor voice, and other voice parts woven around it that contain occasional short canons but are saturated with motives dervied from the opening notes of the cantus firmus.


Canonic fragments in "Si la face ai pale"

Ockegham also used canon and was a master of it, but his application was so subtle and understated that the listener did not apprehend canonic sections even as they unfolded. In the music of Josquin, the canons are deliberate and obvious, and attention is paid that the identity of the cantus firmus is not obscured.

In application, Dufay and his fifteenth-century contemporaries most often restricted imitative procedures to occasional important structural points such as section beginnings. The imitative subjects could be derived from the cantus firmus but, often, they were formulated to fit the cantus firmus without drawing their contours from it. The subjects were generally recognizable only in their opening notes, even if the subject was protracted. In this usage, then, the opening notes function as an identifiable motive before continuing in free polyphony. Nonetheless, one finds a more systematic and logical application of motives then in chant, early organum, or the isorhythmic music of the Ars nova.