A comparison of various steel-string acoustic guitars’ modal response with relation to typical playing styles

Steel-string acoustic guitars are built with large variations in geometry and materials, leading to different-sounding instruments. Musicians will have preferences for geometries or woods depending on certain musical styles or personal preferences regarding tonal characteristics. For example, dreadnought-style guitars with either mahogany or rosewood back and sides and a spruce top are overwhelmingly preferred for bluegrass music. This work presents the beginnings of a project to collect measurements from a vast and varied collection of guitars attempting to span the ranges of guitar woods and geometries. Vibration and acoustic measurements of the instruments are captured and modal analysis is performed to extract the modal frequencies, damping ratios, and amplitudes of the prominent modes. The modal characteristics among them are compared to better understand the most prominent differences with an attempt to learn why certain geometries or woods are preferred for specific genres of music and playing styles. The dataset is continuing to grow and currently includes measurements of twenty different guitars.