the range of sources gradually widened to include other sacred sources and even sometimes popular songs. The cantus firmus was at first restricted to the tenor, but by the end of the century many composers experimented with other ways of using it, such as introducing it into each voice as a contrapuntal subject, or using it with a variety of rhythms. During the 16th century the cantus firmus technique began to be abandoned, replaced with the parody (or imitation) technique, in which multiple voices of a pre-existing source were incorporated into a sacred composition such as a mass. Yet while composers in Italy, France, and the Low Countries used the parody and paraphrase techniques, composers in Spain, Portugal, and Germany continued to use the cantus firmus method in nationally idiosyncratic ways. Probably the most widely set of the secular cantus firmus melodies was "L'homme armé". Over 40 settings are known, including two by Josquin des Prez, and six by an anonymous composer or composers in Naples, which were intended as a cycle. Many composers of the middle and late Renaissance wrote at least one mass based on this melody, and the practice lasted into the seventeenth century, with a late setting by Carissimi. There are several theories regarding the meaning of the name: one suggests that the "armed man" represents St Michael the Archangel, while another suggests that it refers to the name of a popular tavern (Maison L'Homme Armé) near Dufay's rooms in Cambrai. Being that this music arose shortly after the Fall of Constantinople in 1453, it is possible that the text "the armed man should be feared" arose from the fear of the Ottoman Turks, who were expanding militarily towards central Europe. There are numerous other examples of secular cantus firmi used for composition of masses; some of the most famous include: "Se la face ay pale" (Dufay), "Fortuna desperata" (attributed to Antoine Busnois), "Fors seulement" (Johannes Ockeghem), "Mille Regretz", and "Westron Wynde" (anonymous). German composers in the Baroque period in Germany, notably Bach, used chorale melodies as cantus firmi. In the opening movement of Bach's St Matthew Passion, the chorale "O Lamm Gottes, unschuldig" appears in long notes, sung by a separate choir of boys "in ripieno". As a teaching tool Using a cantus firmus as a means of teaching species counterpoint was the basis of Gradus ad Parnassum by Johann Joseph Fux, although the method