Hesiod, the Homeric Hymns, and Homerica

The early Greek epic—that is, poetry as a natural and popular, and not (as it became later) an artificial and academic literary form—passed through the usual three phases, of development, of maturity, and of decline. No fragments which can be identified as belonging to the first period survive to give us even a general idea of the history of the earliest epic, and we are therefore thrown back upon the evidence of analogy from other forms of literature and of inference from the two great epics which have come down to us. So reconstructed, the earliest period appears to us as a time of slow development in which the characteristic epic metre, diction, and structure grew up slowly from crude elements and were improved until the verge of maturity was reached. …