HERINGTON, N. ... et al, 2010. Normal modes of a Gamelan Gong. 1st EAA Euroregio: Congress on Sound and Vibration, Ljulbjana, Slovenia, 15th-18th September.
A gamelan is an ensemble of traditional musical instruments from Indonesia and
surrounding countries. The backbone of a gamelan is a selection of gongs with a wide
range of sizes but a characteristic general shape. Compared with many other
percussion instruments these gongs have been incompletely investigated. In the present
work we report a study of the normal modes of one particular small gamelan gong
originating in Sarawak. A finite-element model of the gong has been constructed and
used to calculate the forms and frequencies of its normal modes. These are compared
with experimental ESPI results. Agreement is reasonable in view of the lack of
precision in the manufacture of the instrument. They show exactly what one would
expect of an axially symmetric system subject to reasonably small symmetry breaking.
A comparison with the acoustical power spectrum enables us to identify the small
number of modes mainly responsible for sound output.