38 Chapter 3
Figure 3.3
Gregorian chant In exitu Israel in tonus peregrinus , the “ wandering tone, ” so named because it “ wanders ” from
the first reciting tone on A (first measure) to another on G (second measure) ( ♪ sound example 3.1). Text: “ When
Israel came out of Egypt and the house of Jacob from a strange country. ”he show any awareness of Copernican astronomy. Both doctrinally and cosmologically,
Glarean was conservative; he remained loyal to the Roman church and strongly distanced
himself from the Protestant reformers, yet was proud to be a friend of Erasmus.
Though he was no heliocentrist, Glarean ’ s musical work opens a new perspective on
whether a seemingly immovable center can move. In compositions throughout the Middle
Ages, whether chant or polyphonic works, the mode remained as unmoved as the Earth
in Aristotelian physics. Only in the Tonus peregrinus ( “ wandering ” or “ foreign ” mode) of
chant was there the possibility of moving between modal centers, as in the chant sung by
the pilgrims at the beginning of Dante ’ s Purgatorio , the aptly chosen In exitu Israel
( “ When Israel Came Out of Egypt ” ; figure 3.3 ; ♪ sound example 3.1). But here too the
chant eventually reaches a final pitch that situates it within a regular mode.^3
In the course of presenting his novel modal ideas, Glarean also discusses ways of chang-
ing the modal center. He notices that such possibilities are beginning to be used by con-
temporary composers, whose practices confirm his theories by showing that, by habitually
adding a B ♭ to the Lydian mode, those composers essentially are writing in the Ionian
(modern major) mode starting on F ( figure 3.4 ; ♪ sound example 3.2). Such a shift from
Lydian to Ionian he considers “ scarcely clear even to a perceptive ear, indeed often with
great pleasure to the listener, ” indicating the possibility of other, more radical changes:
“ But in other cases the changing seems rough, and scarcely ever without a grave offense
to the ears, as changing from the Dorian to the Phrygian. From this I believe the adage
arose: from Dorian to Phrygian, from natural to less natural, or from well-ordered
to irrational, or from mild to harsh; briefly, from whatever, as they commonly say, does
not keep to its course and falls from this into a different one. ”^4 The adage questions the
status of any such fundamental change, whether in the divine order, the human polity,
or music.
Aristotle considered the “ manly ” Dorian and “ emotional ” Phrygian so opposed that
when Philoxenus (an avant-garde practitioner of the Greek New Music discussed in chapter
1) tried to sing a Dionsyiac dithyramb in the Dorian mode, he “ fell back by the very
nature of things into the more appropriate Phrygian. ”^5 One would expect as conservative
a thinker as Glarean to reject change of mode, yet he notes that new compositions force
a reconsideration: “ But enough now of philosophizing. Josquin des Prez in the psalm De
profundis , has undertaken successfully to go from Dorian to Phrygian, skillfully and