Javanese gamelan music comes in two scales, or laras: sléndro and pélog. Neither of the scales are compatible with Western tuning because the intervals, or pitch steps between subsequent notes, are different. Even gamelan instruments of different sets do not have exactly the same intervals between notes. This means that gamelan instruments must be played as sets, but this also give individual character to different gamelan ensembles.
Sléndro is a pentatonic or five-note scale consisting of the pitches 1 2 3 5 6. (Also see gamelan notation.) While not the same as Western pitches, you can get some idea of the sléndro scale by playing the black keys on a keyboard.
Pélog is a seven-note scale consisting of pitches 1 2 3 4 5 6 7. Because of the "foreign" musical intervals, pélog may sound somewhat dissonant to Western ears.
Pieces come in pathet, or modes, of scales (similar to the modes of church music in the Middle Ages). There are three modes for each scale: sléndro nem, sanga, and manyura and pélog lima, nem, and barang. These modes stress specific pitches. This means that normally, most pélog pieces will be played using only five of the seven pitches (there are exceptions).Author: Bern Jordan.