The Balinese orchestra is called a gamelan. Strictly the word refers to the instruments, not the players. The Bali-Hindu religion requires the gamelan for the success of the thousands of ceremonies performed every year. There are more than two dozen distinct types of gamelan, each with their own traditions, repertoire and social or religious functions. The music is full of insistent rhythms and elegant patterns. There is hardly any improvisation.

The primary function of gamelan music, as with everything else in Bali, is to entertain the gods and deified ancestors at various ceremonies. There is music at temple ceremonies, weddings, cremations, family temple ceremonies and processions. The players rehearse frequently and memorize the music. There are also secular performances, and of course, many tourist performances too. Often the musicians have other jobs during the day and meet in the evening to practise or perform.

Instruments

The mainly percussion instruments are played in unison:

Gangsas
These comprise a number of different sized instruments, metallophones that look like xylophones, called gangsas, which have bronze keys that are hit with little wooden hammers which causes bamboo resonators below the keys to vibrate. They may have four to 14 keys and are grouped in pairs. After the keys have been hit by the hammer in the right hand, the left hand immediately grasps the key to stop the sound merging in the next note.

Gongs
There are a number of single fine bronze gongs, which are hit at intervals with a cloth-covered mallet, to divide up the composition.

Ceng-ceng
These are small bronze cymbals, which add colour and excitement.

Reyong
This is a long framed instrument holding about a dozen inverted bronze pots, having small knobs on top, bosses, which are hit with sticks by four players sitting alongside, each player being responsible for his own section.

Trompong
Sometimes there is a second similar instrument, called a trompong, which is played by only one person, whose arms need to be long; this, along with the suling and rebab, are the only instruments which improvise.

Kendang
These are two sets of double-ended drums, held across the lap, lead the orchestra; in each pair, there is a higher pitched one, designated male and a lower-pitched one, female. The kendang is considered the most difficult instrument in the gamelan.

Suling
High pitched flutes, suling, are often part of the gamelan.

Rebab
The rebab is an ancient two-stringed instrument like a violin.

Scale
Usually only five tones are used - a pentatonic scale. All the instruments have unchangeable pitches - except for the rebab. They are tuned when the instruments are made, which means they don't tune up before a performance. There is no universal norm for tuning - the tuner decides on his own, which means that each set of instruments has its own characteristic sound and stays together.

Every pair of instruments is tuned so that one is tuned slightly higher than the other one. When they are hit simultaneously, the difference in pitch, caused because the sound waves emerge at slightly different speeds, produces a third note, called the beat note, that gives a very lively throbbing sound.

Lead
The drums lead but they are not visible to all members of the orchestra, so the lead gangsa player often flourishes his hammer to guide the others. The compositions always end with a big gong beat.

Melody
The tuned instruments play the melody or a variation of it, while the large gong and smaller gongs, cymbals and drums keep time and furnish a framework for the melody. The higher the pitch of the instrument, the more complicated the music it has to play.

So, the melody, played by the gangsa, trompong, sulings and rebab, is propelled and controlled by the pair of drums and punctuated by gongs. The gongs delineate circular movements of the melody. This contrasts with Western music, which proceeds in a straight line. The structure of the music is akin to birth, death and reincarnation.

Much of the excitement of Balinese rhythms arises out of kotekan, interlocking pairs of gangsa at the upper registers. Two interlocking musical lines sound as one melody. They could not be played alone. They are often played at unimaginable speed. The two drummers also play in patterns that are similar to kotekan.

History
There are musical instruments on the friezes of Borobudur Temple, near Jogjakarta in central Java. The arrival of bronze from mainland Asia was the necessary breakthrough for music in Java and Bali. Smiths learned how to cast gongs and later forge keys. Then tuning evolved and ways of assembling instruments.

One of the earliest gamelans is the Gamelan Gambuh, still played in a few villages, including Batuan, but more common is a gamelan called the Gamelan Gong Kebyar. This type produces really intense, loud, lively, exciting music, with rapid changes of tempo, full of sudden starts and stops. This is in stark contrast to the older Javanese gamelan, from which it evolved, which is very sedate indeed.

The courts in Bali were patrons. Because of their isolation from each other, there were and remain a great variety of musical styles. The Dutch fostered relations with the kings, but the courts declined in influence following colonisation. Ownership of gamelans increasingly belonged to the banjars and the common people. The Gamelan Gong Kebyar was founded in the North Balinese villages and caught on like wildfire. It is now so familiar it is just called Gong.

Colin McPhee writes in his book Music in Bali that the Gong Kebyar was first introduced in Bungkulan village in 1914 and spread to almost every other village in Buleleng regency by the early 1930s, when it reached the height of its popularity. The word Kebyar derives from byar which means sudden intense sound or flash of light.

In those days it was often performed during a cremation. Consisting of at least 35 musicians and perhaps two or three ensembles, playing over two or three consecutive days, the cost demonstrated a person's social status. There has since been pressure to simplify cremation ceremonies and people now tend to hire smaller groups of angklung or gambang music groups.

In south Bali Gong Kebyar is known as Kakul and in Tabanan as Mongol. One artist from Tabanan, Mario, became famous for his Kebyar Duduk (the seated Kebyar) dance.

In the early 1960s a High School, KOKAR, and a College of Performing Arts, STSI, formerly ASTI, were established in Denpasar and have a high reputation for teaching, research and creating new works.

As with Balinese painting, tourism has provided a new kind of patronage, which has helped finance the purchase of gamelans, whilst civic pride has kept standards high. Ubud and Peliatan are particularly well regarded.

The Bali Arts Festival in Denpasar every June and July features performances from all over the island.