Evelyn Lamb writes about mathematics and other cool stuff. Follow on Twitter
The four test guitars. Image courtesy of Kazutaka Itako and Satoshi Itako.
The MTV Video Music Awards are being broadcast tonight. Since 1984, these awards have recognized the top popular musicians, videos, and songs each year. Young musicians who dream of one day having their very own “Moonman” statue might be interested in getting the best guitar for their money. Luckily, science is here to help.
Kazutaka Itako is an electrical engineer at the Kanagawa Institute of Technology in Japan, but he has played the guitar since he was six years old. Satoshi Itako has a master’s degree in electrical engineering but works as a guitar fabricator. Together, the brothers have been investigating the optimal shape for guitars.
Experts have settled many questions surrounding the best shape for violins, but far less research has been done on guitars. The brothers’ preliminary work, presented at the Acoustics 2012 conference in Hong Kong in May, looks at one variable: guitar depth. They crafted four nearly identical guitars, ranging in depth from 58 to 98 mm.
They tested the four guitars using both objective and subjective measures of tone quality while a performer played open strings with two different strumming styles. They used an oscilloscope to measure the inclusion of harmonics, an index of the depth and richness of a tone. In addition, nine musically trained listeners rated the guitars.
The 68 mm thick guitar had the highest inclusion of harmonics, and six of the nine listeners rated it as having the best tone quality. The performer also reported that the 68 mm guitar was the easiest to play. The larger guitars were cumbersome, and the smaller one seemed unstable.
The Itako brothers have now moved on to the question of how the size of the sound hole influences the guitar’s tone. After that, they would like to study the effect of material. Kazutaka Itako says it is time-consuming and expensive to produce wooden guitars. He would like to determine whether a synthetic material, like fiberglass, could make instruments that are just as sonorous as wooden instruments.
Of course, at very high levels of performance, players’ individual tastes will probably determine the kinds of guitars they choose. The Itakos’ goal is to find the ideal dimensions and materials for a high-quality sub-professional instrument, allowing more amateur strummers to buy good instruments at affordable prices.