Twelve Books on Harmony

Book One

Sound is not distinct from motion. It is not necessary to invent a new entity, or a new quantity or quality, since everything reported about sound can be correctly explained through motion, as will be more clearly established from the things to be said.

From this, it follows that the object of Music is not well-defined simply as a number of sounds, unless by "number" you mean the counted number of motions. Therefore, Music is not as subordinate to Arithmetic as people usually think, nor even to Geometry. It only needs these as handmaids and instruments to express the various ratios of motions.

Furthermore, anyone who wishes can confirm that sound is nothing other than the motion of air from the Philosopher Aristotle in Book 2 of On the Soul, Chapter 8, text 12. There, after saying air lacks sound because it is easily dissipated, he adds that the motion of air, when it is prevented from dissipating, is sound: original Greek: "ὁ τόπος κίνησις ψόφος" (ho topos kinēsis psophos) "the place, the motion, the sound." He repeats this in text 16.

I set aside the opinion of Democritus and others who contend that sounds are nothing but the leaping out of nearly infinite atoms or corporeal particles. These particles would spring out from strings or other sounding bodies in almost the same way that particles of sweet-smelling flowers exhale, or as bright atoms emerge from the Sun. Whether these particles come from the sounding bodies themselves, or belong to the air, or are the air itself leaping here and there like a shell or glass that shatters into many pieces when struck against a rock, philosophers dispute the true meaning of Democritus and Epicurus. But whatever this or that person thinks about sound, the things that follow will be safe.

PROPOSITION III.

Air, water, and other liquids are the proper subject, or matter, or place, in which sound is produced.

The body in which sound occurs must be easily moved so that it reaches the ears quickly. This is why a motion made in milk or oil is hardly heard. This is clear from a bell whose clapper, although struck against the edge of the bell, produces no sensible sound in those two liquids. However, it does produce sound in water and wine. In these, the sound is one tenth part deeper and heavier than in air, as will be said elsewhere.

Furthermore, air is the most noble and suitable original: "idoneum" subject of sound, since it is the most mobile of all bodies we use. It is worthy of a philosopher to contemplate and test the changes in sounds that happen due to differences in the mediums. A person will have made no small progress in musical matters if, knowing the density of a liquid, they can predict the sound that will occur in it. Or, having heard the sound, they can assign the density of the liquid or medium in which it occurs, or other properties of the medium, if there are any.

PROPOSITION IV.

In order for the following propositions to be true, whether sound does not differ from motion or is distinct from it, let it be established that sound is the object of hearing, or that it is perceptible by hearing.

I have added this so that no hypothesis or preconceived opinion might hinder this treatise on music, and so the rest may proceed correctly. I do not want someone adhering to the particular opinion of certain physicists, who make sound a quality distinct from motion, to think that the following propositions depend on that opinion which I declared in Proposition 2. These propositions will abstract from every opinion, as is proper, so that there is no error or falsehood for the abstracting musician. There is no one who denies or doubts that sound is the object of hearing, so that what has been brought forward so far can be counted among the given facts.

Next, let us show that sound agrees with light in many properties and differs from it in many others. Since nothing seems better known than light, it will bring clarity to the obscurity of sounds. Furthermore, since sound consists in motion, it might seem that a treatise on motion should come first. However, that should be sought from Physics, although many things about it will be explained in the course of this work.

PROPOSITION V.

To explain the properties in which light and sound agree.

There are many things in which sound agrees with light, from which the nature of sound will be more clearly understood;

First, every particle of both spreads itself in a circle. This is common to all agents that have a sphere of activity. However, I am not discussing here whether the same particle of air or light that comes from the mouth, or from a sounding and shining body, travels through the whole sphere of activity. Or, whether the first particle of air, by whose motion sound is produced, does not pass further, but agitates other nearby particles with a similar motion. This difficulty requires another place for discussion.

Second, light and sound are diminished or increased more according to how far or near they are from the efficient causes from which they are first made. This is common to other qualities and accidents. We will say in another place by what ratio they are diminished and increased. Bacon Mersenne uses the name "Verulamius," referring to Francis Bacon, Lord Verulam added in his Sylva Referring to Bacon's Sylva Sylvarum, or A Natural History that the species of sound enter through the pores of the air just like the species of colors, unmixed and distinct. But since sound does not differ from motion, or since that lack of mixing of sounds is not at all true, as will be demonstrated in its place, I omit this analogy.

Third, they agree in this: both are easily generated and perish, though in various ways, as we will explain at some point.