Felix Rohner’s scientific contributions

The HANG is a new steel instrument consisting of two spherical shells of steel, suitable for playing with the hands. Seven to nine notes are harmonically tuned around a central deep note which is formed by the Helmholtz resonance. Elliptical note areas are formed on the upper shell and tuned so that the (1,1)a and (1,1)b modes of each note area have frequencies that are in the ratios of 3:2:1 with respect to the fundamental, except in the highest notes where they are in the ratio of 2.5:2:1 or 2.4:2:1. Holographic studies show the modal shapes and also the extent of coupling between note areas.

The ping, which has the same playing range as a tenor steelpan, is a new instrument in the steelpan family. Its playing surface is sandwich hardened steel having a uniform thickness of 0.9 mm, and its skirt is of stainless steel 1.25‐mm thick. Each note area has a small elliptical dome at the center to provide stability and a durable strike point. We compare the modes of vibration of the ping to those of a tenor steelpan. In both pans, the (0,1) mode of each note is tuned an octave above the fundamental, and the (1,0) mode is tuned a twelfth (three times the frequency) above the fundamental in the lower notes. In the ping, it is possible to tune a twelfth throughout more of the range, and the frequency remains unchanged for a longer time during hard playing. Radiation of sound by the skirt is compared.

Modal analysis contributes significantly to an understanding of the vibrational patterns and the rich spectral tone color of the Caribbean steelpan sound. This will be illustrated with several examples of computer animations of steelpan normal modes. In addition to showing some of the low?order modes which contribute strongly to the radiated sound, these animations also show direct linear coupling effects between note sections. Since impact excitation modal analysis is fundamentally a linear experimental technique a solenoid driven excitation hammer minimizes amplitude?dependent nonlinearities. PANART artisans have emphasized tonal consistency through material and processing controls. This includes steel production to pan crafters specifications, custom drum manufacture, and a systematic sandwich surface hardening process. A European cultural influence has led to some departure from traditional Caribbean standards. Examples of note spectra and modal analysis computer animations will be shown.

The HANG is a new musical instrument, suitable for playing with the hands, consisting of two hemispherical shells of nitrided steel. It is the product of a collaboration among scientists, engineers and hangmakers, thanks to which we have been able to better understand the tuning process in all its complexity. Seven notes are harmonically tuned around a central deep tone (ding), which excites the Helmholtz (cavity) resonance of the body of the instrument. There are many ways to play the HANG. We show the different stages of its development over the seven years since its birth in 2000. We describe the tuning process and the musical conception of the HANG.

The HANG is a new hand-played steel instrument developed by PANArt in Switzerland. We describe the modes of vibration, observed by holographic interferometry and the sound radiation from the instrument, observed by measuring the sound intensity in an anechoic room. A low-voice HANG is compared with a high voice-HANG.