A chord is the overlaying of more than one note. Harmony refers to the progression of chords.

When we play for the first time, we become aware that some notes go together better than others. This gives us the idea that there could be an affinity between certain notes.

• From an historical-scientifical point of view all sorts of things have been written from different sources saying similar yet different things.
• From a sensorial point of view we perceive some sounds as being more harmonic, which is to say more in tune with one another.

A chord, an ‘accord’, is a pact, a cohesion, when more things are united.

In music a chord is the consonance of at least two notes.

Like when we slide a key into a lock and hear click, meaning that the key has fit and has opened the lock.

In much the same way, sound is created by the meeting of multiple frequencies: their collision determines a centripetal tension (a level of tension) which is translated by the ear’s timpanum into a timbre, into a specific note (or chord).

That sound is therefore determined by the encounter between the subjective perception of the timpanum and the objective mechanism that is the collision of the frequencies against the timpanum.

In 1974 a book called Sound — From Physics to Man, to Music, to Machine, Pietro Righini metaphorically explains the relationship between two frequencies as the relationship between two runners:

“Two runners run a track circuit; if in the time during which one of them completes, let’s say, 20 laps, the other completes 24, it is evident that in the time period under consideration they will find themselves together four times and at opposite sides of the track four times, along with all the intermediary positions involved […] In the moments in which the two runners are together, which represent the concordances of phases, you have the sum of two effects of the same signal, while in the moments of opposition the negative signal effect counterposes the positive one. […] When the you replace the runners in the example with sound vibrations you have, as a consequence of the alternation between concordant and oppositional phases, further increases and decreases in the intensity of sound.”

The effect of sound, the pitch, the intensity, the volume and the timbre, are therefor effects determined by the relationship between two speeds and their balance.

This, with time, tends to stabilise, acquiring a specific meaning, a tonal definition. It thus becomes a precise note which, as it diffuses, transforms into its harmonics.

Harmonics are the components of the initial sound. Just as green is composed of the combination of blue and yellow, so E and B are harmonics of G.

 

A fundamental sound is broken down into its harmonic components:

 

Proceeding theoretically in this way we can reach an infinitely finite number. Finite because we started from a single sound which, ‘in a certain way’, created a starting point. In this case it imposed the tonality within which it is possible to retrace the constituent parts.