Roman comedy is mainly represented by two playwrights, Plautus (writing between c.205 and 184 BC) and Terence (writing c.166-160 BC). The works of other Latin playwrights such as Livius Andronicus, Naevius, Ennius, and Caecilius Statius are now lost except for a few lines quoted in other authors. 20 plays of Plautus survive complete, and 6 of Terence. Various metres are used in the plays. As far as is known, iambic senarii were spoken without music; trochaic septenarii (and also iambic septenarii and trochaic and iambic octonarii) were chanted or recited (or possibly sung) to the sound of a pair of pipes known as tībiae (the equivalent of the Greek aulos), played by a tībīcen ("piper"); and other metres were sung, possibly in an operatic style, to the same tībiae. In Plautus about 37% of lines are unaccompanied iambic senarii, but in Terence more than half of the verses are senarii. Plautus's plays therefore had a greater amount of musical accompaniment than Terence's. Another difference between the playwrights was that polymetric songs (using metres other than iambic and trochaic) are frequent in Plautus (about 14% of the plays), but hardly used at all by Terence. The different metres lend themselves to different moods: calm, energetic, comic, mocking, high-flown, grandiose, humorous, and so on. Certain metres are also associated with different kinds of characters; for example, old men frequently use iambic senarii, while the iambic septenarii are often used in scenes when a courtesan is on the stage. The metres of Roman comedy tend to be more irregular than those of the classical period, but there is an opportunity to hear in them the rhythms of normal Latin speech. Cicero wrote of the senarius: "But the senarii of comic poets, because of their similarity to ordinary speech, are often so degraded that sometimes it's almost impossible to discern metre and verse in them." (en)