A new tuning method for glass harp based on a vibration analysis that uses a finite element method

Abstract

When using wine glasses as musical instruments (also referred to as the glass-harp), the pitch needs to be minutely adjusted. That is, it needs to be tuned. A wide adjustment range has been achieved by a new method that locally shaves the bottom of the cup of each vessel circumferencially. The pitch decreased in proportion to the quantity of glass shaved. This relationship between the quantity of glass shaved and the change in pitch was clarified both experimentally and analytically by Finite Element Method (FEM) analysis. The amount of pitch change accompanied with the shaving method is occasionally limited by the vessel shape. In such cases, pitch can be changed by filling wine glasses with specific quantities of water, a well-known conventional tuning method. This auxiliary method has been measured experimentally and analyzed by FEM to clarify the relationship between the water quantity in vessels and the amount of pitch change. A harmonics analysis was also performed. Using these procedures, prediction of vibration frequency could be done in advance, which means a desired pitch can be easily obtained.