Actor in Greek is "Hypocrit ês", that is, "responder". Two groups of chorus: one group jumps to the left, the other group jumps to the right, and the lead singer of each group is the "Answers".

The poet plays a hero, a legendary king or a god in the play. In the past, a complete choir consisted of 50 actors and a poet. This is all the members of the tragedy, namely: 1 poet, 2 responders (choir leaders) and 48 dancers. There are 12 singers and dancers in the "Four Quju" every time.

According to an ancient inscription found, comedy only appeared in bacchanalia, with a lively form. The parade of actors on the stage promoted the development of comedy, because at this time they can "speak freely". Contrary to serious tragedy, comedy entertains the audience with impromptu gags. The purpose is to purify people's hearts.

If tragedy arouses people's pity and shock through the destruction of beauty, so that people can distinguish right from wrong and purify their hearts, then comedy can vent people's crazy emotions in a humorous and lively form, and can also make people calm and purify their hearts. They achieve the same goal through different routes, which are two different aspects of the same thing.