Parts move in perfect parallel 4ths, 5ths, or octaves.
Octave doublings create compound parallel organum.
The chant melody in the vox principalis is on top, and the newly-composed organal voice begins in a unison with it, then moves through 2nds and 3rds to a parallel 4 th away. In the second A and B section octave doublings are introduced to produce compound modified parallel organum. The parts often move in contrary motion, and they cross in a number of places. As it appears in the manuscript, the piece is through-composed. Benedicamus Domino trope in note against note free organum, with vox principalis on bottom, vox organalis on top.