Gamelan
Gamelan is the traditional ensemble music of the Javanese, Sundanese, and Balinese peoples of Indonesia, made up largely of percussion instruments, but also including some aerophones and chordophones and sometimes voice. To sound in tune, the latter instruments must match some of their harmonic partials with the inharmonic partials of the percussion instruments. The people of Indonesia settled upon two different tuning systems to accomplish this, called Slendro (close to but not exactly 5edo with stretched octaves) and Pelog (similar to but noticeably different from a 2L 5s scale of 9edo with octaves ranging from slightly compressed to slightly stretched). In both systems, the tuning (including the octave stretch or compression) is not exactly the same between octaves, to accommodate differences between the instruments made for the different octaves. This is explained in the following video, which also gives a brief introduction to the instruments of gamelan ensembles:
Further reading
- Pleng: Composing for a Justly Tuned Gender Barung. - Article by Bill Alves about certain Slendro and Pelog scales of Indonesia
- Alunan gamelan mana paling bagus? (Which gamelan game is the best?) - A comparison of audio-video recordings of gamelan orchestras from different regions of Indonesia
- r/GlobalMusicTheory's list of sources about gamelan theory; many academic papers
- Gamelan Music of Java: an Introduction - Video introduction, with Hardja Susilo
- A Guide to the Gamelan, Neil Sorrell - Book
- American Gamelan Institute - Including the Balungan journal and a library of further resources