Instruments of the Central Javanese Gamelan: An Introduction

This is the first in a series of articles exploring the various instruments of the Javanese gamelan. We start off with an overview of this fascinating topic.

If you were to travel to the islands of Java or Bali, you would very likely encounter the music of the gamelan, an ensemble of traditional instruments for which Indonesia is famous. There are numerous types of gamelan ensembles found across this diverse archipelago. Each has its own instrumentation, associated musical style, tuning, and cultural context. The Javanese gamelan tradition was cultivated in the palaces of Central Java as early as the second century CE. Because of its historical connection to the royal courts and their patronage, the music has developed into a highly refined art form and, like the classical music of Europe, has come to carry great cultural prestige.

Most of the instruments of the gamelan are struck idiophones, a class of instruments that produce sound when the primary material of the instrument itself vibrates. They are made of hand-forged bronze, suspended on wooden frames. The gamelan ensemble can also include drums, stringed instruments, and wooden xylophones. All pieces of the ensemble are ornately decorated with hand-carved designs and shimmering gold paint.

The instruments of the gamelan can be divided into three families: balungan instruments, punctuating instruments, and elaborating instruments.

The balungan instruments—the saron, the demung, the peking, and the slenthem—carry the melodic lines. For these, players strike the instrument’s bronze bars with a mallet while dampening with their other hand to control the length of each note. Balungan in Indonesian means “skeleton,” which reveals a powerful perspective on how Indonesians perceive melody. A skeleton holds our body’s structure but is not seen from the outside. Similarly, a balungan melody should be strong but subtle. As with our bones, it should not be prominent. 

Unlike Western art music, which tends to be linear, gamelan music is cyclical, or colotomic. Colotomic time cycles are marked by the second family of instruments, the punctuating instruments. Most important in this family, and in the ensemble as a whole, is the largest gong, the gong ageng. It marks the beginning/ending of each cycle and is thought to hold the spirit of the gamelan, reflecting the strong mysticism that Javanese people still hold today. The gong ageng and the kempul, which are smaller gongs, are hung from wooden frames and struck in the center with a padded mallet.

The kenong, kethuk, and kempyang are sets of inverted pots that are supported by rope in wooden frames. All three instruments are played by one musician, who uses two mallets, one in each hand. The kendang, or drum, punctuates the time cycles and is considered the leader of the ensemble. Much like a conductor in a western orchestra, the kendang player navigates the musicians through tempo changes, starts and stops, and accentuates other collaborative art forms such as tari (dance) and wayang kulit (shadow puppets). All of the punctuating instruments help in marking time in the gong cycle.

The third family, the elaborating instruments, help add shape and movement to a piece, as well as anticipate where the balungan line is headed next. In so doing, these instruments—each following its own special rules of elaboration—play what is known as an “inner melody” to the balungan line. There are many elaborating instruments in the Javanese gamelan ensemble, including a two-string bowed fiddle called a rebab, a zither called a siter, a wooden xylophone called a gambang, a bronze metallophone called a gendèr, and a row of small bronze pots suspended over a wooden frame called a bonang. Vocalists are also included in this group. Each elaborating instrument follows its own special rules of ornamentation.

Central Javanese gamelan music uses two scales: pelog, which consists of seven notes, and slendro, which has five. The two scales are performed on separate sets of instruments, and gamelan ensembles may have one or both sets. There is no strictly prescribed tuning for either scale. The concept of laras, or how the scale should sound, was historically both subjective and protected, a choice based on aesthetic differences from village to village. This means that different gamelans using the “same” scale might have distinct root pitches, and the intervals between any two notes in the scale might vary, minutely or substantially, creating subtle differences in the mood or feeling of the music.

As in other elite musical traditions, the various instruments of the Central Javanese gamelan embody fascinating differences in construction, timbre, and performance methods. Learn more about the individual instruments as we add profiles of each in this ongoing series.