Etymologiae, Book III, chapters 21-22: De secunda divisione, quae organica dicitur to De tertia divisione, quae rythmica nuncupatur
Chapter XXI. On the second division, which is called organic The second is the organic division, in those things which, filled by returning breath, are animated into the sound of voice, such as trumpets, reeds, pipes, organs, the pandora and like instruments. Organum is a general word for all musical vessels. That, however, to which bellows are applied, the Greeks call by another name. That it is called organum is rather the common custom of the Greeks. The trumpet was first invented by the Tyrrhenians, of whom Virgil says: “And the Tyrrhenian blare of the trumpet roared through the heavens.” It was used not only in battles but on all festal days for the brightness of praise or joy. Hence it is said in the Psalter: “Blow the trumpet in the new moon, on the noted day of your solemnity.” For it had been commanded to the Jews to sound the trumpet at the beginning of the new moon, which they also do to this day. Pipes (tibiae) are said to have been devised in Phrygia: these for a long time were used only at funerals, soon also at the rites of the Gentiles. They think they were called tibiae because they were first made from the shin-bones and legs of fawns, then, by misuse, those also began to be so called which were not made of legs and bones. Hence also tibicen, as if the song of pipes. Calamus is the proper name of a tree, named from calendo, that is, pouring forth voices. Some think the pipe (fistula) was invented by Mercury, others by Faunus, whom the Greeks call Pan. Some say by Idas, a shepherd of Agrigentum in Sicily. The fistula is so called because it sends out voice. For phōs in Greek is voice, and stoma is called mouth. The sambuca among the musical instruments is a species of symphonies. For it is a kind of fragile wood, from which pipes are composed. The pandorius is named from its inventor. Of which Virgil:
“Pan first taught to join several reeds with wax, Pan cares for the sheep and the masters of sheep.” For among the Gentiles he was a pastoral god, who first fitted unequal reeds to song and composed them with studious art.
Chapter XXII. On the third division, which is called rhythmic The third is the rhythmic division, pertaining to strings and beat, to which are given the species of various citharas, also the drum, the cymbal, the sistrum, bronze and silver bowls, or other things which, struck with a metallic stiffness, give back with sweetness a ringing, and the rest of this kind. The discoverer of the cithara and psaltery is said to be Tubal, as was said before. According to the opinion of the Greeks, however, the use of the cithara is believed to have been found by Apollo. The form of the cithara is said to have been at first like the human breast, so that as the voice comes from the breast, so from it song should be given forth, and for the same reason it was so called. For the breast in the Doric tongue is called chitara. Gradually, however, many species of it arose, such as psalteries, lyres, barbitons, phoenices and pectides, and those called Indian, which are struck by two at once. Likewise others and others, of square form or triangular. The number of strings also was multiplied, and the kind changed. The ancients called the cithara fidicula or fidex, because its strings agree among themselves as well as it befits those among whom there is faith (fides). The ancient cithara had seven strings. Hence Virgil: “Seven distinctions of voices.” Distinctions, because no string gives back a sound like that of the neighbouring string. But the strings are seven either because they fill the whole voice, or because the heaven sounds with seven motions. Chords (chordae) are named from the heart (cor), because as there is the pulse of the heart in the breast, so the pulse of the string in the cithara. Mercury first devised these, and he first stretched sound into strings. The psaltery, which is commonly called a canticle, is named from psalling, because the chorus answers its voice by sounding together. It is like the barbarian cithara in the manner of the letter delta; but between the psaltery and the cithara there is this difference, that the psaltery has that hollow wood, from which the sound is returned, above, and the strings are struck downward, and sound from above. The cithara has the hollow of the wood below. The Hebrews used a ten-stringed psaltery on account of the number of the Decalogue of the law. The lyre is named from lyrein, that is, from the variety of voices, because it produces diverse sounds. They say the lyre was first invented by Mercury, in this way. When the Nile, returning into its channels, had left various animals in the fields, a tortoise also was left behind. When it had putrefied, and its sinews had remained stretched within the hide, struck by Mercury it gave a sound; after its pattern Mercury made the lyre and handed it to Orpheus, who was most zealous in this matter. Hence it is thought that by the same art he applied the modulation of song not only to wild beasts but also to rocks and woods. The musicians, for love of their study and the praise of song, feigned in the inventions of their fables that this too was placed among the stars. The drum is a skin or hide stretched on wood on one side. For it is the middle part of a symphony in the likeness of a sieve. The drum is so called because it is the middle, whence a pearl is also called a middle drum; and it, like the symphony, is struck with a rod. Cymbals are certain bowls which, struck against each other, touch and make a sound. They are called cymbals because they are struck together with ballematia; for the Greeks say kym and ballō. The sistrum is named from its inventress. For Isis, queen of the Egyptians, is proved to have invented this kind. Juvenal: “And let Isis strike my eyes with her angry sistrum.” Hence women also strike this, because the inventor of this kind was a woman. Hence also among the Amazons the army of women was called to war by the sistrum. The little bell (tintinnabulum) has its name from the sound of the voice, as also the clapping of hands, the creaking of doors. The symphony is commonly called a hollow piece of wood with skin stretched on both sides, which the musicians strike with rods from this side and that, and there is made in it from the concord of low and high a most sweet song.