An Eighth

That this is the first of all Consonances, and that which is the most easily perceived by the Hearing after an Unison, is manifest from the Premises, and also comprobated by experiment in Pipes: which, when blown with a breath stronger than ordinary, instantly yield a sound more Acute one Eighth. Nor is there any reason, why that sound should immediately arise to an Eighth, rather than to a Fifth, or any other Note; unlesse because an Eighth is the first of all Consonances, and that which is the least different from an Unison. From whence, we conceive, it doth also follow, that no sound can be heard, but it seems in some sort to refound in the ear more Acute an Eighth: and that this is also the cause, why in a Lute to the greater strings, which give Graver sounds, other smaller strings more Acute one Eighth are consociated, which are alwayes percuffed at the same instant, and so effect that the Graver sounds are heard more distinctly. Whence it is manifest, that no sound which shall be consonant to one Term of an Eighth, can be dissonant to any other Term of the same Eighth.

A second thing to be observed concerning an Eighth, is this; that it is the greatest of all Consonances, that is, that all other Consonances are contained therein; or composed [11] thereof, and of others which are contained therein. Which may be demonstrated from hence, that…