Balinese music represents, to a large extent, a survival of the pre-Islamic music of Java. It was taken to Bali by Hindu Javanese in the 15th cent. and uses the tonal systems of Javanese music, of which pelog is by far the more important in Bali. Balinese music sounds impetuous and noisy, in contrast to the soft, tranquil music heard currently in Java. Few gamelans, the orchestras of tuned percussion instruments, play in Java today but they flourish, their archaic forms preserved, in modern Bali. The gamelans of the princes are no longer important in Bali, but have left their influence on the village societies for music making. There are also the ceremonial gamelans of the temples.

The most important gamelan instruments are xylophones, which may be made of bronze or bamboo. Bronze xylophones are of two basic types—gangsa, whose keys are supported over a wooden resonance box, and g'ndér, whose keys have individual bamboo resonators. These instruments sometimes play the melody and sometimes they provide a brilliant figuration. Gongs, suspended singly, are used for metrical accentuation; there are also gong chimes, which are of two types. The trompong, a set of 10, is a solo instrument, and the réyong, a set of 12, is played by four men, supplying figuration. Flutes, in two sizes, are made of bamboo and are used in theatrical music. Although the name of the rebab, a two-string spike fiddle, is Persian-Arabic, the instrument probably originated in S China and is used in the music of the gambuh play. Cymbals, bell rattles, and drums supply the all-important elaborate rhythmic background. The anklung is an archaic, tuned bamboo rattle. It is not known in all parts of Bali, but gives its name to the anklung gamelan, a ceremonial gamelan which may at one time have always included anklungs.

The instrumentation and the repertory of a particular gamelan depend on its function. Each of the various forms of dance and drama has a gamelan which specializes in its music. The most recent musical development is kebyar, a restless, explosive music which discards the highly developed, balanced forms of the older music. Kebyar clubs compose their own music, often taking themes from older music. The wealthier clubs include a dancer—a young man who performs seated on the ground, dancing from the waist up. Balinese notation was invented by the Javanese who brought the music to Bali. It gives no indication of the rhythm and is little used. Music is learned by rote; it is not improvisation, however, but a sophisticated, composed art form. Balinese music has had some popularity in the West, mainly sponsored by the composer Lou Harrison, founder of the modern American gamelan movement.

See D. A. Lentz, The Gamelan Music of Java and Bali (1965); C. McPhee, Music in Bali (1965).