Bonang

The bonang consists of two rows of horizontal gong-kettles with the open side facing down, which is placed on cords stretched over a rectangular wooden-frame. A full gamelan set has two kinds of bonang: bonang barung and bonang panerus; the latter is one octave higher than the former (its lower octave overlaps with the higher octave of bonang barung). Depending on the tuning system, a bonang may have fourteen gong-kettles for pelog (seven in each row), or twelve or ten for slendro (six or five in each row). Some gamelan may also have bonang panembung, a bonang whose octave range is one octave lower than bonang barung.

Bonang barung is one of the leading instruments in the gamelan ensemble. The anticipatory nature of its playing technique can be used as a melodic guide for the ensemble in expressing its melodies. Particularly, the playing style known as pipilan (playing single notes one at a time) leads the flow of the melody, and certain gembyangan (octave playing) are used as a sign for melodies in high octave ranges that are unattainable by the saron. There is another bonang playing technique that requires two bonang, bonang barung and bonang panerus, which creates interlocking melodic patterns using a technique called imbal-imbalan.

Evidence of gong-kettle type instruments can be found in the drawings of these instruments on the walls of old temples. The drawing of gong-kettles on the wall of the 14th-century Panataran temple in East Java is quite revealing. It consists of two small gong-kettles vertically mounted on two side ends of a bar. (This instrument can still be found and played in contemporary Bali). Perhaps there was a period of development from this type of instruments to instruments with gong-kettles resting on a frame with the open side facing down, such as bonang, kethuk-kempyang, and kenong. As gamelan developed into an expansive ensemble, together with the emergence of repertoire that employs wider registers, bonang with wider octave range were constructed to accommodate this development.