Pelog
Pelog is one of the two essential scales of Gamelan music native to Bali and Java, in Indonesia. The other is slendro. The Pelog scale can be constructed in the same way as the Western diatonic scale, as a chain of perfect fourths, except with very wide, out-of-tune fourths, between 515 and 535 cents. This is at the very extreme of the range of intervals that can be perceived as a fourth, and rapid beating between the upper harmonics (actually inharmonic overtones in the case of the metallophones which form the bulk of the gamelan orchestra) contributes to the unique shimmering sound of the gamelan. The full pelog scale has seven distinct tones (a stack of 6 fourths), but normally a composition would be written in a 5-tone subset of the full scale. The seven tones of the pelog scale, in circle-of-fourths order, are called "barang", "dada", "nem", "gulu", "lima", "bem", and "pelog" (yes, same as the name of the scale). Therefore, the tones of the scale in ascending order, with the two different kinds of step interval labeled L and S, are: gulu-S-dada-L-pelog-S-lima-S-nem-S-barang-L-bem-S-gulu. In this case S is about 110-150 cents and L is 250-300 cents.The cents measurements above are just from one example of a Javanese Pelog scale. Pelog scales can and do vary widely from island to island, province to province, and even town to town (Bali is a good example of where this happens). There is disagreement among musicologists about what exactly makes a pelog scale a pelog scale. More importantly, Indonesians until quite recently never measured or analyzed their scales using the western measurements of pitch and cents. Pelog, from an Indonesian point of view is much more about the feeling of the scale. Anyone trying to understand this scale should not try to do so analytically until they understand the music and culture it comes from.