The great variety of ensembles is at least partly due to the history and geography of Bali. As on most Indonesian islands, repeated waves of immigration and movement of populations has led to a rich and varied culture. Bali is a relatively small island (much smaller than its near neighbor Java, the other Indonesian island with a famous gamelan tradition), but until the twentieth century, its remoteness and geography as a small island dominated by volcanoes, thick forests, and deep ravines, allowed its various communities and small kingdoms to develop distinctive local religious and entertainment traditions.
While Java was largely converted to Islam, Bali has retained this diversity of local Hindu religious practices. Religion is an important part of the culture of Bali, and a very important aspect of Balinese gamelan music. There are literally thousands of different ceremonies associated with Balinese Hinduism, and gamelan music is an important element of many of these ceremonies.
Gamelan music was probably imported to Bali from Java. Both traditions began as upper-class court music, and the gamelan practices of the two islands still share many important similarities. But because Islam officially disapproves of music, Javanese gamelan practices are much less likely to be associated with religion. The quieter, more improvisational style of Javanese gamelan reflects a fairly continuous history as a classical music for upper-class courts. On Bali, on the other hand, the royal courts lost their power and influence during the period of Dutch control in the early twentieth century, at which time community cooperatives took over much of the performing arts traditions. The louder and more intensely cooperative Balinese music has been strongly influenced by village traditions using gamelan for the people's ceremonies and celebrations. The difference between the two islands' music is easily audible even to the average Westerner.
Note:
Because of the religious associations, the playing area and the instruments themselves are treated with great respect. To avoid giving offense, Westerners who do not know the proper way to do this should keep a respectful distance from the ensemble.
Many of the instruments are very carefully crafted, not only to give beautiful and very-carefully-tuned sounds, but also to be visually pleasing works of art. The wooden frames that hold the instruments are often intricately carved and brightly painted, usually with instruments in a particular gamelan carved and painted to look like, as well as sound like, a matching set.
There are dozens of different types of gamelan. Some types are found in almost every community, others in only a few isolated villages. Each type of gamelan has its own established tradition that includes a standard repertoire of music, in forms specific to that ensemble, to be played in a particular context. As already noted, some of these contexts are religious; one type of ensemble may be found in funeral processions, for example, or at particular temple celebrations.
Other gamelan may provide music for a specific kind of dance or theater performance. For example, wayang kulit, the famous shadow-puppet theater, is traditionally accompanied by a gender wayang ensemble, while dance-dramas may be accompanied by gamelan gambuh.
Specific kinds of dance may also call for specific kinds of ensembles. The conception of dance is also somewhat different from Western ideas; when a performance includes dance, the dance and music are considered to be intensely interdependent, two aspects of a single artistic expression, rather than separable "accompaniments" to each other. Traditionally, women are more likely to be dancers and men are more likely play instruments, but some traditional dances are for men, and it is more common now for women to also play in the gamelan.
Bali has much to celebrate and most months of the year have something of interest happening, with various seasonal things to do and tourist-friendly events taking place, often within the countless temples. March is one of the most important festival months on Bali, with the exciting Melasti and Nyepi religious festivals taking place and always being the cause for much celebration.