In Attica an important alteration was made in the old tragedy in the time of Pisistratus, in consequence of which it obtained a new and dramatic character. This innovation is ascribed to THESPIS, a native of the Attic village of Icaria, B.C. 535. It consisted in the introduction of an actor for the purpose of giving rest to the chorus. Thespis was succeeded by Choerilus and Phrynichus, the latter of whom gained his first prize in the dramatic contests in 511 B.C. The Dorian Pratinas, a native of Philius, but who exhibited his tragedies at Athens, introduced an improvement in tragedy by separating the Satyric from the tragic drama. As neither the popular taste nor the ancient religious associations connected with the festivals of Dionysus would have permitted the chorus of Satyrs to be entirely banished from the tragic representations, Pratinas avoided this by the invention of what is called the Satyric drama; that is, a species of play in which the ordinary subjects of tragedy were treated in a lively and farcical manner, and in which the chorus consisted of a band of Satyrs in appropriate dresses and masks. After this period it became customary to exhibit dramas in TETRALOGIES, or sets of four; namely, a tragic trilogy, or series of three tragedies, followed by a Satyric play. These were often on connected subjects; and the Satyric drama at the end served like a merry after-piece to relieve the minds of the spectators. The subjects of Greek tragedy were taken, with few exceptions, from the national mythology. Hence the plot and story were of necessity known to the spectators, a circumstance which strongly distinguished the ancient tragedy from the modern. It must also be recollected that the representation of tragedies did not take place every day, but only, after certain fixed intervals, at the festivals of Dionysus, of which they formed one of the greatest attractions. During the whole day the Athenian public sat in the theatre witnessing tragedy after tragedy; and a prize was awarded by judges appointed for the purpose to the poet who produced the best set of dramas.