Page:Pratt - The history of music (1907).djvu/71

 the latter have the final in the middle and the dominant two or three steps above it. Strictly speaking, each pair of modes is really one, the difference between authentic and plagal being in practical application.

To these earlier modes four more were added, making twelve—the first statement of the complete series being by Glarean in 1547. Two more were proposed, but rejected. The Church Modes                                                  Ancient Names 1. Dorian              D EF  G A* BC D } Phrygian  2. Hypodorian    A BC D EF* G A       }  3. Phrygian            EF G A  BC* D E } Dorian  4. Hypophrygian  BC D EF G A* B       }  5. Lydian              F G A  BC* D EF } Hypolydian  6. Hypolydian    C D EF G A* BC       }  7. Mixolydian          G A BC  D* EF G } Hypophrygian  8. Hypomixolydian D EF G A BC* D      } or Iastian 9. Æolian              A BC  D E*F G A } Hypodorian  10. Hypoæolian   EF G A BC* D E       } or Æolian

11. Ionian             C D EF  G* A BC } Lydian  12. Hypoionian  G A  BC D E*F G       }     In each case the final is marked by a black letter, the dominant by an asterisk. The essential difference between the modes lies in the location of the short steps, as well as of the finals and dominants. While melodies in the several modes were primarily intended to be sung at the pitch above indicated, they might be transposed to fit the voice. The 'ambitus' or compass of a melody properly does not exceed the octave of its mode by more than one step above or below. In strictness, no deviations from the above scales are permitted, but the direct progression from F to B or vice versa (the tritone) was ruled out as unsingable, and, to avoid it, Bb was substituted for B wherever the latter occurred in relations suggesting the above progressions. Ultimately, however, under the name of 'musica ficta,' much more extensive alterations of the modes were practised (see sec. 73). 28. The Hexachord-System.—By the 11th century, if not before, the whole series of tones found useful for song was reduced to a system like the Complete System of the Greeks (see sec. 20). But it was longer than the latter and laid out, not in tetrachords, but in hexachords—series of tones standing in the relation of C-D-E-F-G-A. To facilitate practice, the syllables ut, re, mi,