American gamelan music. Lou Harrison and William Colvig, who met in 1967 in San Francisco, built a set of tuned percussion instruments that they called "an American gamelan" in order to differentiate it from Indonesian ensembles. It was first used in Harrison's work "La Koro Sutro" in 1972. These are now referred to as "Old Granddad", and Harrison wrote some pieces that can only be played on this set, including "La Koro Sutro". Lou Harrison spent some time with a Javanese gamelan in 1976 (when Kyai Udan Mas, now at the University of California, Berkeley, was in residence at San Jose State
Gamelan interference beats are meant to give the listener a feeling of a god's presence or a stepping stone to a meditative state. The scale roughly approximates that of the phrygian mode of the Western major scale (E-E on the white keys of the piano), with the notes EFGBC corresponding to the note positions 12356 in the "slendro" scale used by most gamelan. As well as the non-western octave and the use of beats, Javanese gamelan uses a combination of tempo and density known as "Irama", relating how many beats on the "saron panerus" instrument there are to notes in the