At a certain point, Plato complained about the new music:
Our music was once divided into its proper forms...It was not permitted to exchange the melodic styles of these established forms and others. Knowledge and informed judgment penalized disobedience. There were no whistles, unmusical mob-noises, or clapping for applause. The rule was to listen silently and learn; boys, teachers, and the crowd were kept in order by threat of the stick. . . . But later, an unmusical anarchy was led by poets who had natural talent, but were ignorant of the laws of music...Through foolishness they deceived themselves into thinking that there was no right or wrong way in music, that it was to be judged good or bad by the pleasure it gave. By their works and their theories they infected the masses with the presumption to think themselves adequate judges. So our theatres, once silent, grew vocal, and aristocracy of music gave way to a pernicious theatrocracy...the criterion was not music, but a reputation for promiscuous cleverness and a spirit of law-breaking.
Playing what "sounded good" violated the established ethos of modes that the Greeks had developed by the time of Plato: a complex system of relating certain emotional and spiritual characteristics to certain modes (scales). The names for the various modes derived from the names of Greek tribes and peoples, the temperament and emotions of which were said to be characterized by the unique sound of each mode. Thus, Dorian modes were "harsh", Phrygian modes "sensual", and so forth. In his Republic, Plato talks about the proper use of various modes, the Dorian, Phrygian, Lydian, etc. It is difficult for the modern listener to relate to that concept of ethos in music except by comparing our own perceptions that a minor scale is used for melancholy and a major scale for virtually everything else, from happy to heroic music. (Today, one might look at the system of scales known as ragas in India for a better comparison, a system that prescribes certain scales for the morning, others for the evening, and so on.)
The sounds of scales vary depending on the placement of tones. Modern Western scales use the placement of whole tones, such as C to D on a modern piano keyboard, and half tones, such as C to C-sharp, but not quarter-tones ("in the cracks" on a modern keyboard) at all. This limit on tone types creates relatively few kinds of scales in modern Western music compared to that of the Greeks, who used the placement of whole-tones, half-tones, and even quarter-tones (or still smaller intervals) to develop a large repertoire of scales, each with a unique ethos. The Greek concepts of scales (including the names) found its way into later Roman music and then the European Middle Ages to the extent that one can find references to, for example, a "Lydian church mode", although name is simply a historical reference with no relationship to the original
From the descriptions that have come down to us through the writings of those such as Plato, Aristoxenus and, later, Boethius, we can say with some caution that the ancient Greeks, at least before Plato, heard music that was primarily monophonic; that is, music built on single melodies based on a system of modes/scales, themselves built on the concept that notes should be placed between consonant intervals. It is a commonplace of musicology to say that harmony, in the sense of a developed system of composition, in which many tones at once contribute to the listener's expectation of resolution, was invented in the European Middle Ages and that ancient cultures had no developed system of harmony—that is, for example, playing the third and seventh above the dominant, in order to create the expectation for the listener that the tritone will resolve to the third.
Yet, it is obvious from the following excerpt from Plato's Republic that Greek musicians sometimes played more than one note at a time, although this was apparently considered an advanced technique. The Orestes fragment of Euripides seems to clearly call for more than one note to be sounded at once.. There is also intriguing researce in the field of music from the ancient Mediterranean—decipherings of cuneiform music script—that argue for the sounding of different pitches simultaneously and for the theoretical recognition of a "scale" many centuries before the Greeks learned to write, which of course would have been before they developed their system for notating music and recorded the written evidence for simultaneous tones. All we can say from the available evidence is that, while Greek musicians clearly employed the technique of sounding more than one note at the same time, the most basic, common texture of Greek music was monophonic.
That much seems evident from another passage from Plato:
...The lyre should be used together with the voices...the player and the pupil producing note for note in unison, Heterophony and embroidery by the lyre--the strings throwing out melodic lines different from the melodia which the poet composed; crowded notes where his are sparse, quick time to his slow...and similarly all sorts of rhythmic complications against the voices--none of this should be imposed upon pupils...
Music was essential to the pattern and texture of Greek life. Certain Greek philosophers saw a relationship between music and mathematics, and envisioned music as a paradigm of harmonious order, reflecting the cosmos and the human soul.Although the Greeks knew many kinds of instruments,they used two above all: lyres and auloi (pipes). Most Greek citizens were trained to play an instrument competently, and to sing and perform choral dances. Instrumental music or the singing of a hymn regularly accompanied everyday activities and formal acts of worship. Shepherds piped to their flocks, oarsmen and infantry kept time to music, and women made music at home. Musicians performed in contests, at the drinking parties known as symposia, and in the theater.The art of singing to one’s own stringed accompaniment was highly developed. However, despite the wealth of circumstantial evidence, the sounds of ancient Greek music are lost to us