FÉTIS defines music as the art of moving the emotions by combinations of sound. This statement would give to the tonal art a very early origin, and would even allow it a pre-human existence in the songs of birds. The beginning of human music must have been vocal in character. Herbert Spencer considers song as a form of expression arising from the reflex action of the vocal organs under stress of emotion, just as a cry follows pain. This would reverse the definition of Fétis, and make music a result of emotion rather than a cause.
It seems probable that the early songs developed from hunting- calls, or other vocal signals employed in primitive life. As soon as such calls were used for the pleasure expressed or imparted, apart from any useful purpose, they became music in the strict sense of the term. Melody would thus arise easily from the amplification of a single call or the union of several. Some authorities think that song was first an accompaniment to the muscular expression that led to dancing; but the hunting-signals probably antedated the rudimentary tangos of the primitive races.
The origin of different scales may be traced with more detail, even if some of it is legendary. Our own scale is "founded on fact," for Pythagoras brought its mathematical relations from Egypt, and made them the basis of the Greek scales. In this system the pitches of the notes corresponded to definite fractional parts of a stretched string. The Greek system became the basis of the Ambrosian and Gregorian modes, described in detail in a later chapter; and the same pitches were employed in the diatonic mode that replaced these. For the last two centuries the intervals, by common consent, have been altered slightly, to make our twelve equal semi- tones that permit of modulation from one key to any other.