It is very difficult to understand the relation which music bore to the exhibition of Roman comedy. It is clear that there was always a musical accompaniment, and that the instruments used were flutes; the lyre was only used in tragedy, because in comedy there was no chorus or lyric portion. The flutes were at first small and simple; but in the time of Horace were much larger and more powerful, as well as constructed with more numerous stops and greater compass.[165] Flutes were of two kinds. Those played with the right hand (tibiæ dextræ) were made of the upper part of the reed, and like the modern fife or octave flute emitted a high sound: they were therefore suitable to lively and cheerful melodies; and this kind of music, known by the name of the Lydian mode, was performed upon a pair of tibiæ dextræ. The left-handed flutes (tibiæ sinistræ) were pitched an octave lower: their tones were grave and fit for solemn music. The mode denominated Tyrian, or Sarrane,[166] was executed with a pair of tibiæ sinistræ. If the subject of the play was serio-comic, the music was in the Phrygian mode, and the flutes used were _impares_ (unequal,) _i. e._, one for the right, the other for the left hand.[167] In tragedy the lyrical portion was sung to music and the dialogue declaimed. But if that were the case in comedy, it is difficult to imagine what corresponded to the lyrical portion, and therefore where music was used. Quintilian informs us that scenic modulation was a simple, easy chant,[168] resembling probably intonation in our cathedrals. Such a practice would aid the voice considerably; and if so, the theory of Colman is probably correct, that there was throughout some accompaniment, but that the music arranged for the soliloquies (in which Terence especially abounds) was more laboured and complicated than that of the dialogue.[169] In order to understand the principles which regulated the Roman comic metres, some remarks must be made on the manner in which the language itself was affected by the common conversational pronunciation. In most languages there is a natural tendency to abbreviation and contraction. As the object of language is the expression of thought, few are inclined to take more trouble or to expend more time than is absolutely necessary for conveying their meaning: this attention to practical utility and convenience is the reason for all elliptical forms in grammatical constructions, and also for all abbreviated methods of pronunciation by slurring or clipping, or, to use the language of grammarians, by apocope, syncope, synæresis, or crasis.