The Greeks used music chiefly as an adjunct to their poetry, and were accustomed to chant long epics in what would seem to us a monotonous sing-song, generally if not always without accompaniment. Their love for moderation and their avoidance of the passionate, harsh, or over-expressive, moreover, impelled them to exclude from their gamut both the lowest and the highest tones of the voice, so that even their tonal material was confined to a range of about two octaves. The tones included in this limited range, however, they classified and disposed with the greatest ingenuity. The intervals at which tone should follow tone were dictated by seven arbitrary schemes called modes, and each mode was supposed to have its peculiar quality of expression. Thus the Lydian mode, corresponding to our modern major scale, was considered voluptuous and enfeebling, while the Doric mode, an idea of which may be gained by playing a scale, all on white keys, beginning with E, was thought to breathe manliness, vigor, and dignity. They used no harmony, and introduced rhythm only by the metre of the verses sung. Consequently it is easy to see that they can have had from their music but little æsthetic delight, which depends on the grouping into harmonic or rhythmic forms of the tonal material; but must have valued it chiefly for its sensuous beauty, and for its power to enhance the expressiveness of their poetry. It is nevertheless noteworthy that all three kinds of value did exist in the music of the Greeks, though the third was still in a rudimentary stage. As a result of the generally equal length of their verses or lines of poetry, the melody that accompanied them tended to be divided into equal sections remotely resembling our modern “phrases”; and these sections tended to balance each other, and so to give the sense of symmetrical form. Furthermore, it was customary to end each line with a fall of the voice analogous to the downward inflection of a speaking voice at the end of a sentence. These downward inflections, called cadences, from a Latin verb meaning “to fall,” afforded a convenient means of dividing off the musical as well as the poetic flow into definite parts like segments in a piece of bamboo or the inches on a tape-line; and in the subsequent development of musical structure these divisions, marked by cadences, became the indispensable elements in a highly complex organism. Thus the Greeks, in spite of the immaturity of their music, considered in and for itself, did actually make valuable contributions to the progress of the art. Their period was one of promise rather than of fruition; but it contained the seeds of further growth. It is often called the Monophonic or “one-voiced” period, from the fact that their chants were purely melodic, employing but one voice at a time, without harmonic support.