On Senecan Tragedy

I recently finished reading a collection of Seneca's tragedies. While these works have much to recommend, it was interesting to see to what extent Seneca had no idea what a chorus in a tragedy did or was for. He seemed to include them simply because Greek tragedies had them. Each tragedy had the chorus appear at the end of each act, sort of as an afterthought. So it seem that by the Roman times, the understanding of what a chorus in a tragedy did or was there for was already lost.