These two harmonies I ask you to leave; the strain of necessity and the strain of freedom, the strain of the unfortunate and the strain of the fortunate, the strain of courage, and the strain of temperance; these, I say, leave.
And these, he replied, are the Dorian and Phrygian harmonies of which I was just now speaking.
Then, I said, if these and these only are to be used in our songs and melodies, we shall not want multiplicity of notes or a panharmonic scale?
I suppose not.
Then we shall not maintain the artificers of lyres with three corners and complex scales, or the makers of any other many-stringed curiously-harmonised instruments?
Certainly not.
But what do you say to flute-makers and flute-players?
Would you admit them into our State when you reflect that in this composite use of harmony the flute is worse than all the stringed instruments put together; even the panharmonic music is only an imitation of the flute?
Clearly not.
There remain then only the lyre and the harp for use in the city, and the shepherds may have a pipe in the country.
That is surely the conclusion to be drawn from the argument.
The preferring of Apollo and his instruments to Marsyas and his instruments is not at all strange, I said.
Not at all, he replied.
And so, by the dog of Egypt, we have been unconsciously purging the State, which not long ago we termed luxurious.
And we have done wisely, he replied.
Then let us now finish the purgation, I said.

Next in order to harmonies, rhythms will naturally follow, and they should be subject to the same rules, for we ought not to seek out complex systems of metre, or metres of every kind, but rather to discover what rhythms are the expressions of a courageous and harmonious life; and when we have found them, we shall adapt the foot and the melody to words having a like spirit, not the words to the foot and melody.

To say what these rhythms are will be your duty--you must teach me them, as you have already taught me the harmonies.
But, indeed, he replied, I cannot tell you.

I only know that there are some three principles of rhythm out of which metrical systems are framed, just as in sounds there are four notes (i.e.the four notes of the tetrachord.) out of which all the harmonies are composed; that is an observation which I have made.

But of what sort of lives they are severally the imitations I am unable to say.
Then, I said, we must take Damon into our counsels; and he will tell us what rhythms are expressive of meanness, or insolence, or fury, or other unworthiness, and what are to be reserved for the expression of opposite feelings.