Slendro

What it means

Slendro is a five-note scale of Indonesian gamelan music, above all in Java and Bali. Its five steps lie roughly equally far apart, so that the octave is divided roughly into five equal intervals.

This distinguishes it from Western pentatonic scales, whose steps are unequal and rest on whole tones, semitones, or minor thirds.

Musical use

Alongside slendro, gamelan music uses the seven-step pelog with clearly unequal intervals. A gamelan ensemble usually has separate sets of instruments for the two systems, each tuned accordingly.

The tuning is not standardized: each gamelan has its own individually tuned slendro scale whose intervals differ somewhat from ensemble to ensemble. Exact cent values can therefore be given only for a particular instrument set, not for slendro in general.

Slendro should be distinguished from the Western pentatonic scale and from the equal division of the octave into five, which comes close as a theoretical model but is not tuned exactly that way in practice.

Performance practice

If you imitate slendro on Western instruments, keep in mind that equal-tempered notes are only an approximation. Listen to recordings of real gamelan ensembles to grasp the characteristic, shimmering color of the tuning.