MUSIC, originally, any art over which the muses presided; afterward, that science and art which deals with sounds as produced by the human singing voice, and by musical instruments. The science of music includes several branches: (1) The physics, that is, the analysis of the cause and constitution of sound, the number of atmospheric vibrations which produce given sounds, and the arrange ment of series of sounds standing in a definite relationship to each other as re gards their vibration-number (scales) ; also, the form and construction of in struments with reference to the character and nature of the sounds they produce; and, also the apparatus of experimental acoustics, such as sound-measures (to nometers, sirens, tuning forks, etc). These branches, of course, involve prob lems of pure mathematics. (2) The physiology of music. This deals with the construction and functions of the sound producing organs of the human body, the vocal chords, larynx, etc., and, also, with the receptive organ of sound, the ear. (3) The mental philosophy of music, that is, the effect of music on the emotions and :ntellect. The art of music includes the formation of melody (sounds in suc cession), and harmony, and counterpoint (sounds in combination) ; also, the "tech nique" of voice production and singing, and of performing on musical instru ments. The earliest efforts of mankind in music consisted in the elevation and depression of the voice in reading sacred writings and lyrical poetry, and in the construction of pipe instruments, tubes pierced with holes (flutes), tubes con taining a vibrating tongue (reed instru ments), and collections of pipes in which the sound was produced by making the breath or other column of air impinge on a sharp edge (the syrinx and the organ), in using the lips as a cause of vibrations in open tubes (the trumpet family), in the stretching of strings in a frame (the lyre and harp family), in placing stretched strings over a resonance box (the lute and guitar family), in the use of the "bow" to excite vibrations (the viol family), and in the striking of strings over a resonance box by means of hammers (the dulcimer and harpsichord and pianoforte family).
The ancient signs for the elevation and depression of the voice in reading were called accents (not stress, but the raising and the dropping of the voice without adding to its force). These led to a system called neumes; these again led to signs called notes, the position of which on lines showed their pitch, and the shape of which determined their duration. The use of letters in various positions to represent definite sounds was an es sential element of ancient Greek music, which, however, was discarded at the revival of music in the early Christian Church; but the system has, in an im proved form, been revived in the modern tonic sol-fa system.