Daniel Colin at his home in Ivry Sur Seine

When I hear an accordion on the radio, on TV, or in a well-sounded concert, I always guess easily and very quickly if the instrument I hear is a Cavagnolo. The only time I was wrong, the accordion I heard was a Maugein!^[1]  Now, knowing that the Cavagnolo family came from Italy to settle in Paris in 1924 to make accordions and that Maugein is a maker of instruments in the pure French tradition, I came to the conclusion that there was indeed a specific French sound of the accordion. I still had to prove it, hence this article.

First of all, let's try to understand how a sound is produced.

The eardrum of our ear is a kind of infinitely thin membrane capable of capturing infinitely small variations in the air pressure produced by any mechanical system. Our eardrum works in the same way as a microphone. Let us note right away that what differentiates a musical sound from a noise is the fact that the components of a musical sound are voluntarily organized by the maker of the instrument while a disordered accumulation of sounds is perceived as being a noise.

Let's take a piano string as a model.

The pitch of the sound is influenced mainly by the length of the string, its diameter and its density. The lowest string of a piano can measure up to two meters long while the highest is only six centimeters! If we wanted to keep the same diameter and density for all the strings of a piano, the string of the lowest note would measure more than six meters (22 ft.). This is why we voluntarily increase the diameter of the bass strings to reduce their length. The middle A string which vibrates at 440 vibrations per second (1 vibration per second = 1 hertz or Hz) measures approximately 42 centimeters. If we cut this string into two equal parts (21 cm.), each of these two parts will vibrate at 880 Hz, therefore, at the higher octave.

Similarly, if we cut this string into three equal parts, we would obtain three strings which would each vibrate an octave plus a fifth higher than our first string A, that is to say the note E.

Furthermore, the intensity of the sound is produced by the greater or lesser movement that the string makes in the air. If I strike the lowest string of the piano fff, that is to say with force, the movement of the string will correspond to, say five millimeters, which will have the effect of producing large variations in the pressure of the air that reaches our eardrum, hence the effect of feeling this sound as being louder than an attack at ppp. Conversely, for the attack ppp, that is to say weak, the string will only move one or two millimeters. It will then no longer move as much air, therefore, the variations at our eardrum will be less and consequently we will feel this sound as being weaker. This movement which defines the intensity of a sound is called the amplitude.^[2]

Now let's see what makes one sound different from another.

What we hear in any musical sound (apart from the tuning fork) is actually a multitude of sounds. Let's take our piano string example. Even though we perceive the note as A 440 Hz, we actually hear many more notes than that. Why?

Because the string does not vibrate only along its entire length!

Indeed, it also vibrates on different sections of its length, in particular, in its two halves, its two thirds, its four quarters, etc. These are called harmonics. The A 440 Hz for example, we hear it because the string vibrates on its entire length, which is called the fundamental of the partial sounds. Because the string also vibrates in its two halves, we also hear the A 880 Hz, that is to say an octave higher, which is called the first harmonic or second partial sound. The string also vibrating on its three equal parts gives us the octave plus the upper fifth, the second harmonic, third partial sound. The four quarters of this same string give us to hear the A 1760 Hz (440 Hz X 4 = 1760 Hz), that is to say two octaves higher and so on for nearly sixteen partial sounds heard. When we say that a string vibrates on both halves of its length, it is as if we were literally cutting the string into two equal parts as I explained above. It is precisely this phenomenon of harmonics that allows us to differentiate instruments. This is what we call the timbre of an instrument.

A sound is said to be rich when it contains many harmonics. A poor sound, on the other hand, will not have many harmonics. A pure sound is a sound completely devoid of harmonics, the tuning fork being the only existing mechanical example. Each part of our string (i.e. its entire length, half of its length, etc.) behaves like a tuning fork. We could even theoretically reproduce any instrument timbre from a series of tuning forks tuned to the model of the harmonics of the instrument we want to reproduce.

Now we are ready to answer our initial question

The audible (perceptible) frequencies for an average human being are between 20 Hz and 20,000 Hz. These frequencies are audible in their entirety until the age of 18 (if our subject has not listened to too much heavy-metal rock at 140 dB!). Already, an adult of thirty years old no longer hears frequencies above 14,000 Hz and the upper threshold of audibility continues to decrease with aging. On the other hand, our ear, as impressive as it is, is in reality very imperfect. It does not hear all sounds with the same sensitivity. It is much more sensitive to sounds that are between 3,000 Hz or 3 kilohertz or 3 kHz (1 kilo = thousand) and 5 kHz which corresponds to the upper octave of the piano. Because musical instruments are generally rich in harmonics, we still have many frequencies to hear above 5 kHz and of course, all the fundamental notes of the piano are located below these frequencies. We will call the frequencies and the region between 3 kHz and 5 kHz, sensitive. Now, it is important to specify that a nasal sound often contains frequencies from the sensitive region of the ear, and in too great a quantity. This same sound then seems shrill and aggressive to us.

But isn't the reed of our accordion made of metal?

Of course! So it tends to produce a metallic sound. The challenge for accordion makers and designers is to make our instrument sound metallic without sounding shrill or nasal. To do this, we need to find ways to bring out the high harmonics without increasing the intensity of the so-called sensitive frequencies (between 3 kHz and 5 kHz). I believe that Maugein and Cavagnolo have achieved this.

I am looking forward to finding the time to make comparative readings on the oscilloscope (a device used to measure sound waves), between different brands of accordion. I will then surely observe that the accordions that sound shrill have a peak (increase) in the sensitive frequencies. Of course there are tricks and recipes to increase the intensity of very high frequencies, here is an example:

French accordion manufacturers use nails instead of the usual wax to hold in place on the wooden soundboards, the plates on which the metal blades are mounted.

Nailed-screwed reed block of the Vedette 10 by Cavagnolo

Is it better?

Yes! Why?

Because a vibratory system must be as rigid and stable as possible to be able to reproduce and support very high frequency harmonics. This is just one example of the relevance of certain details such as the French grilles being more open than the Italian or American grilles. French technicians surely have many other tricks up their sleeve. It is therefore its very high harmonics (between 8 kHz and 17 kHz) that give the sound of the French accordion its peppery and pleasant quality without it sounding aggressive. This sound quality was developed and achieved thanks to the meeting of the two communities (Auvergne and Italian) who together in Paris, forged the foundations of the sound aesthetics of the musette.

Conclusion

Let us be clear on the substance of the subject of our question today.

I have intentionally omitted to talk about the different forms of accordions i.e. piano keyboard versus button keyboard. This area brings us to another topic of discussion that I will address in another article. The way in which the musette register is tuned will also be another topic. These are factors that greatly influence the sound of the accordion I agree, but I have limited myself in this discussion to speaking strictly of the sound source^[3] of the accordion.  And this is the metal free reed and ways to mount it on the reed block.

Note : I have a BRANDONI accordion which is Italian made. I tuned the "violin" register in the French way (i.e. with no more than 1.3 beats per second for the A 440 Hz) and of course it comes closer to the French sound than when it was tuned in the Italian way (4 to 6 beats per second!), but it still doesn't sound like a French accordion! I am convinced that it is the reed itself of the French accordion which gives it its particular sound even if I am told that the quality reeds all come from the same manufacturer! You can reproduce by specifying the source: MARIO BRUNEAU 20-JAN-98

You can reproduce by specifying the source:   MARIO BRUNEAU   JAN-20th-1998

^[1]The accordionist was Daniel Colin

^[2] The greater the movement a sound source makes, the greater the amplitude.

^[3] The sound source of the piano, guitar or violin = the string, that of the trumpet = the lips of the trumpeter, that of the synthesizer = the electronic circuit, etc.