Gamelan with male groups. In the twenty-five countries outside Indonesia that have gamelan, music performed in a concert context or as part of ceremonies for expat communities may also accompany dance or "wayang". The tuning and construction of a gamelan orchestra is a complex process. Javanese gamelan use two tuning systems: "sléndro" and "pélog". There are other tuning systems such as "degung" (exclusive to Sunda, or West Java), and "madenda" (also known as "diatonis", similar to a European natural minor scale). In central Javanese gamelan, "sléndro" is a system with five notes to the octave, with large intervals, while "pélog" has
Gamelan common in national arts conservatories founded in the middle of the 20th century. Gamelan's role in rituals is so important that there is a Javanese saying, "It is not official until the gong is hung". Some performances are associated with royalty, such as visits by the sultan of Yogyakarta. Certain gamelans are associated with specific rituals, such as the "Gamelan Sekaten", which is used in celebration of "Mawlid an-Nabi" (Muhammad's birthday). In Bali, almost all religious rituals include gamelan performance. Gamelan is also used in the ceremonies of the Catholic church in Indonesia. Certain pieces are designated for starting and