A novel method of determining the dynamic properties of an acoustic guitar is presented. As documented in the literature, a modal analysis procedure of the kind described below can be highly advantageous to a luthier as significant insights may be revealed by the identification of the resonant frequencies and mode shapes of an acoustic guitar.

The single-degree-of-freedom (SDOF) modal analysis technique known as the circle-fit method will be employed to evaluate the natural frequencies and resultant low frequency mode shapes possessed by an acoustic guitar whose body is constructed from a variety organic wood species. The technique relies upon the recording of a series of Frequency Response Functions (FRFs) at discrete positions along the length of the guitar

Manipulation of the response and excitation measurements by recourse to the computing environment of a software program such as MATLAB can facilitate the visualisation of the bending mode shapes associated with each mode within the useful frequency range.