EX. 11-2 Benjamin Britten, A Ceremony of Carols, opening of Wolcum yole!That basic harmonic—yes, chordal—to-and-fro so pervades the texture of the Sumer canon that
anyone with half an “ear” (that is, the least bit acculturated into the idiom) could easily get into the swing
of things and extend the piece “by ear” virtually ad libitum with additional simple counterpoints beyond
the twelve written ones, the way kids at the piano do with “Chopsticks” or “Heart and Soul.” And in
bringing up the possibility of “ad-libbing,” we are immediately reminded of Giraldus Cambrensis and his
twelfth-century description of improvisational polyphony (and, just as in Britten’s imaginative
“transcription,” harp playing as well) as practiced in his native Wales, quoted near the beginning of
chapter 5.