Gamelan

A gamelan is an Indonesian musical ensemble mostly made up of metallic xylophones and gongs. Gamelan orchestras are particularly common on the islands of Java and Bali, although they exist on the other islands as well, albeit in slightly different forms.

Although gamelan ensembles sometimes include string and, less commonly, wind instruments, they are most notable for the large number of percussion instruments, particularly metal percussion instruments. A gamelan ensemble may include sarons and genders (sets of bronze bars laid out in a single row and struck like a glockenspiel), bonangs and kenongs (sets of large, drum-shaped gongs, likewise laid out horizontally on stands), gambangs (similar to sarons or genders but with wooden bars instead of metal ones) and a variety of hanging gongs and drums.

Gamelan orchestras use two tuning systems: sléndro[?] is a system with five notes to the octave, fairly evenly spaced, while pélog[?] has seven notes to the octave, with uneven intervals. Most orchestras will include instruments in each tuning, but each individual instrument will only be able to play notes in one. The exact pitches used differs from ensemble to ensemble.

A peculiarity of gamelan instruments is that they do not usually have perfectly tuned octaves. Almost all other instruments tune octaves in the frequency ratio 2:1 (so that an A is 440 Hz, and the A an octave above it is 880 Hz), but gamelan instruments are usually a little sharp or a little flat. It is thought that this contributes to the very "busy" sound of gamelan ensembles.

The gamelan has been an influence on several western composers of classical music, most famously Claude Debussy who heard a Javanese ensemble play at the Paris Exposition of 1889 (World's fair). In more recent times, the American composers Lou Harrison and Evan Ziporyn[?] have written several works with parts for gamelan.