The making of musical instruments such as guitars and violins is known to involve the work of highly experienced and highly skilled craftsmen, but it is also thought to involve much loss due to trial and error. To reduce this loss, in this study we used the MT system to create a measurement scale for guitar tone, and performed parameter design to obtain a provisional ideal tone. The measurement scale is based on the one-sided T test, one of the methods employed in the MT system. Tene difference due to string diameter was used as a signal factor. The fifth string was tuned to A to provide a provisional ideal tone; then the third string was tuned to A, using a graphic equalizer to approximate the same tone. In a first L18 orthogonal array experiment using the standardized S/N ratio, the distance in the MT system approached the normal value, but the sensitivity was not reproducible. Reproducible sensitivity was then obtained through optimization by making a tone transferability evaluation of the factorial effect of the A note of the fifth string, using the distance obtained by the one-sided T test as the characteristic value of the factorial effect. We believe that application of the MT system to sound can help craftsmen in the pursuit of ideal guitars.
