English: Taken from the book "Bach and the Meanings of Counterpoint" by David Yearsley, Cambridge University Press, 2002. Illustration provided by courtesy of Sibley Library, University of Rochester."The volume was reprinted a dozen times in the 17th century and was likely encountered by Bach...the frontispice to Gumpelzhaimer's collection is an engraving of the cross made up of a six part retrograde canon,an allegorical image which links the crucifixion with learned counterpoint..." (David Yearsley)