Bali has several types of gamelan orchestra. The largest (with some 25 players) and best-known types are Gong Kebyar and Semar Pegulingan. Some seventy years ago there were important differences between the two types, but nowadays they are almost alike, both in form and function. The Semar Pegulingan as a rule is higher pitched than the Gong Kebyar and the lead instuments are of a slightly different type.
A gamelan orchestra in Bali consists mainly of two types of instrument: genders and gongs. Each type of instrument has its specific function in the melody and its own playing technique.
Gender - melody and figuration
Genders have bronze keys that are hung over bamboo resonators and are struck with a wooden mallet. These instruments play the core melody and its figurations. All instruments of the gender family are tuned in pairs, the ngumbang ("hummer", the lower-tuned) and the ngisep ("sucker", the higher-tuned).
The corresponding keys of a pair are tuned 4 to 6 Hz apart. When struck simultaneously, this difference in pitch will cause an interference between the sounds. This gives the gamelan of Bali its famous shimmering sound.
Gong - interpunction
Gongs come in three varieties: single hanging or lying gongs that are played by one person each and that give accents to certain fixed points in the melody, sets of ten gongs lying on a frame that are played by one person as a melodic instrument (terompong), and sets of seven or twelve gongs lying on a frame that are played by two resp. four people as a rhythm instrument (reong), used to embellish the main melody.
Kendang - the conductor
The gamelan orchestra is conducted by the kendang, a pair of conical double-ended drums. They come in pairs: the kendang lanang is the higher pitched of the pair, the kendang wadon the lower pitched.
The kendang players sit cross-legged on the ground with the kendang across their laps. The larger drumhead points to the right and is played by the right hand, the smaller is played by the left. Depending on the type of melody, the right head may be played with a drumstick (panggul) or by bare hand. Drumsticks are never used by the left hand.
Gongs, genders and kendangs are the basic elements of a gamelan orchestra. The reong and terompong may be present. The gamelan may be further enhanced with a set of suling (bamboo flutes), a rebab (Arab two-stringed violin) and a ceng-ceng (set of cymbals).