Two related passages in the discussion of mimesis in this part of The Republic are in question here:
Commentators and translators generally agree that Socrates is referring to the effect of imitations of such sounds in performances of drama or dithyramb, and that the mimesis in question is the result of ‘identification’ on the part of spectators. As Adam puts it: ‘In good acting the spectator identifies himself with the actor through sympathy; and as the actor “imitates” so does he.’ Since several of the sounds mentioned would be difficult to imitate effectively by the human voice, Adam and others suggest that the imitative sounds were produced by musical effects and stage-machines (such as the βροντϵȋον). They note that the later ‘degenerate’ dithyrambic performances aimed at mimetic effects of this kind; and so too, of course, did Old Comedy. The three main points in this generally accepted interpretation are:
(a) the mimesis mentioned here is largely a matter of musical reproduction of the sounds listed;
(b) the mimesis consists of direct mimicry of these sounds;
(c) Socrates is referring to dramatic and dithyrambic performances.
There are objections to all of these points. First, against the notion that musical mimesis is primarily or mainly intended: up to this point in the discussion Socrates has confined his remarks to literature. He concludes his literary discussion quite specifically in 398b: ‘Now it looks as if we have completed our survey of the words and myths of μουσική.’ Then he explicitly goes on to consider ‘after this’ the remaining matter, namely, the right kind of ᾠδή and μέλος for the education of the Guardians.