Bonamens is the Latin word for common sense.

Common sense is indispensable when an old piano has to be restored or rebuilt and its mysteries have to be unravelled.The old masters did know how to achieve a good sound with the materials they had at their disposal. That old knowledge is practically lost. In spite of the fact that piano technicians with much improvisation talent are able to deliver a masterpiece.

The talent of Vic Gentils, a Belgian artist, may serve as an example how old pianos can be treated in a very own way. The picture to the right has been borrowed from a monograph, published in 1992 by the “Koninklijk Museum voor Schone Kunsten” in Antwerp. It can be done this way, but the point of this site is merely the sound of old pianos.

For thousands of years mankind has known how strings can be used to produce sounds of a musical nature. The theory behind this knowledge is stubborn.
According to old sources, including legends, in the sixth century B.C. the Greek philosopher Ptyhagoras discovered the tone, produced by a string, is an octave lower when string length is doubled. From the writings of Galileo (1564-1642) it seems clear that he had a good understanding of the dependence of the frequency of a stretched string on the length, tension and density. In 1615 Marin Mersenne published a paper with his findings that the frequency of a string, maintaining tension, is inversely proportional to the length and directly proportional to the square root of the cross-sectional area of the string. In 1713 Brook Taylor published his well-known formula for the frequency of the fundamental vibration of a string.
In the second half of the 18th century mathematicians like Bernoulli, Euler and d’Alembert fought against each other about their solutions for the problems waves and vibrations. From this Lagrange derived a solution for the vibrating string, which is adopted by Lord Rayleigh in his “Theory of Sound”, published in 1877. P. Morse gives in his “Vibration and Sound”, 1936, a derivation of the formula for the partials of a string with stiffness.

The technical successes of the second half of the 20th century led to the belief that the exact sciences could solve every problem. In scientific investigations and studies attempts have been made to catch the sound of pianos in formulas.
The publications show interesting outcomes, but also many contradictions.
Isoharu Nishiguchi, a Japanese investigator, states in his paper 'Recent research on the acoustics of pianos', Acoust. Sci. & Tech. 25, 6 (2004), that it is too early to conclude that the generation mechanism of the piano sound has been clarified qualitatively and that it will take some time to understand the complicated physical phenomena behind a piano tone.

Even with the present sciences and techniques it is possible to produce the sound of a piano but with a piano. This idea is important for everyone who wants to worm secrets out of pianos with a computer. The computer is nothing more than a tool. Like every piece of equipment a computer has to be used with common sense.