a 4 per Augmentationem et Diminutionem, the last in a set of 14 canons written as an appendix to the Goldberg Variations. In the 20th century, one such canon is the Cantus in Memoriam Benjamin Britten by Arvo Pärt (1976). Additionally, Larry Polansky has written numerous four-voice prolation canons whose melodies are permutations of a limited number of elements, and Mark Alburger, in Immortality from San Rafael News, directly maps a new melody into the framework of the aforementioned Josquin. A particularly striking example of prolation canon occurs twice in the opening movement of Shostakovich's Symphony No. 15 (1971), first in the strings (Rehearsal Figure 27) and later in the woodwind at Rehearsal Figure 47. A more recent example of a prolation canon in contemporary music is rindenmotette (2011) by Austrian composer Klaus Lang. References Polyphonic form