How did Plato regard certain “valuable,” forms of art, such as epics or Greek tragedies?

Plato expresses his concern that the arts, because they imitate an imitation, hold no individual value themselves.  How then does he feel about the art he was raised on, such as Greek tragedies and epics, most notably from Homer?  These forms of the arts were often used to set the moral and educational standards for the general public.  One would think that works of art that set moral and ethical codes would indeed have value, and Plato does acknowledge that to some degree.  In short, saying, that while we ourselves would never behave with the shameless lamentation demonstrated by a tragic hero, we can still learn from the overall value of the work as a whole, which is something he feels that most paintings and poems lack.