The Caribbean Steel Pan: Tuning and Mode Studies

Abstract

The evolution of the steel pan during the last half century represents the emergence of a truly new musical instrument. Originating in the folk culture of the Caribbean, it has become popular throughout North and South America, as well as in Europe. The haunting sounds of steel drums, generally called “steel pans” by players and tuners, are now enjoyed worldwide. Pans are usually crafted from commercial 55-gallon steel oil drums. The top with its various openings is discarded, and only the bottom, along with the side, is used for the pan. The length of the side skirt varies depending on the pitch range of the completed instrument. Thus, a bass pan will utilize almost the entire length of the original drum, whereas a lead pan, or a single tenor, will be cut to retain only a very short skirt. The pitch of each note section is primarily determined by the size and geometric shape of the section as bounded by a grooved seam. Figure 1 shows representative layouts of several pans. The note arrangement in some pans is such that several pans are required to play a melody. For example, a double-second instrument consists of two pans, while a bass includes as many as six. In addition to the section size, the mass density, stiffness, and curvature contribute significantly to the pitch of each note. The overall timbre of the tone produced depends to a great extent on the spectral content of the note. This, in turn, depends strongly on the normal modes of the excited note section, and to some lesser extent, on the normal modes of all other sections. This latter dependence is caused by the fact that all note sections are imbedded in the same solid matrix of the drumhead. Therefore, vibrations in one note section cause all note sections to vibrate. The nature of the coupling between sections has been the subject of considerable interest to researchers in the field. Inasmuch as the entire pan represents a highly nonlinear system, the tone quality also varies significantly with excitation amplitude.