The chorus, we have seen, was originally the only celebrant of the Dionysiac festival. As the importance of the actors increased it became less and less vital to the performance. Its numbers, its connexion with the plot, and the length and relevance of its songs, all steadily diminished. Originally there were fifty choristers, but we learn that early in the fifth century there were only twelve, and it is suggested that this change was due to the introduction of tetralogies—the fifty choreutæ being divided as equally as possible between the four dramas. Sophocles, it is said, raised the number to fifteen. This account is doubtful. It is not in the nature of things likely that Æschylus (if it was he) caused or approved such an immense drop in numbers, from fifty to twelve: for the notion that the original chorus was split up into four is frivolous. Is it not obvious that a poet would employ the same choristers for each play of his tetralogy? Again, that Sophocles should chafe at Æschylus’ twelve singers and alter the number, and that by a mere trifle of three, is quite unlikely. There is, moreover, strong evidence that the elder poet used fifty choreutæ, at any rate in his earlier time. The _Supplices_ has for chorus the daughters of Danaus, and their exact number, fifty, was a familiar _datum_ of the legend. The natural view is that Æschylus began with fifty, that Sophocles ended with fifteen, and that between these two points the number gradually sank. Whether the choreutæ after the fifth century became still fewer is not clearly known; there is some evidence that at times they were only seven.