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 Bali, remarked, "Deviations in what is considered the same scale are so large that one might with reason state that there are as many scales as there are gamelans." This view is contested, however, by some teachers of gamelan, and there have been efforts to combine multiple ensembles and tuning structures into one gamelan to ease transportation at festival time. One such ensemble is gamelan "Manikasanti", which can play the repertoire of many different ensembles. Balinese gamelan instruments are built in pairs that are tuned slightly apart to produce interference beats, ideally at a consistent speed for all pairs of