Pelog

Pelog is one of the two essential scales of gamelan music native to Bali and Java, in Indonesia. In Javanese the term is said to be a variant of the word pelag meaning "fine" or "beautiful". The other, older, scale commonly used is called slendro. Pelog has seven notes, but many gamelan ensembles only have keys for five of the pitches. Even in ensembles that have all seven notes, many pieces only use a subset of five notes.

Tuning

Since the tuning varies so widely from island to island, village to village, and even gamelan to gamelan, it is difficult to characterize in terms of intervals. One rough approximation expresses the seven pitches of Central Javanese pelog as a subset of 9-tone equal temperament. An analysis of 27 Central Javanese gamelans by Surjodiningrat (1972) revealed a statistical preference for this system of tuning.

As in slendro, although the intervals vary from one gamelan to the next, the intervals between notes in a scale are very close to identical for different instruments within the same Javanese gamelan. This is not the case in Bali, where instruments are played in pairs which are tuned slightly apart so as to produce interference beating. The beating is ideally at a consistent speed for all pairs of notes in all registers. This contributes to the very "agitated" and "shimmering" sound of gamelan ensembles. In the religious ceremonies that contain gamelan, these interference beats are meant to give the listener a feeling of a god's presence or a stepping stone to a meditative state.