What's Gamelan?

Information edited from Wikipedia:

A gamelan is a kind of musical ensemble of Indonesia typically featuring a variety of instruments such as metallophones, xylophones, drums, and gongs. The term refers more to the set of instruments than the players of those instruments. A gamelan as a set of instruments is a distinct entity, built and tuned to stay together — instruments from different gamelan are not interchangeable. The word "gamelan" comes from the Javanese word "gamel", meaning to strike or hammer, and the suffix "an", which makes the root a collective noun.

Gamelan is found in the Indonesian islands of Java, Madura, Bali, and Lombok (and other Sunda Islands), in a wide variety of ensemble sizes and formations. In Bali and Lombok today, and in Java through the 18th century, the term "gong" has been preferred to or synonymous with gamelan. Traditions of gamelan-like ensembles also exist in the Philippines, Malaysia and Suriname, sometimes due to emigration, historic trade, or diplomacy. More recently, through immigration and local enthusiasm, gamelan ensembles have become active throughout Europe, America, Asia, and Australia.

Gamelan music is built up in layers. At its centre is a basic melody (core melody) known as the balungan. Further layers, including singing in vocal pieces, elaborate upon this melody in certain ways, but the notes of each layer of music relate to the balungan, and generally coincide at the ends of phrases (called seleh in Javanese). There are also a set of instruments which delineate a colotomic structure, usually ending in the stroke of the largest gong.

The gamelan has an old and mysterious origin. Apparently it predates the Hindu-Buddhist culture that dominated Indonesia in its earliest records, and instead represents a native art form. The instruments developed into their current form during the Majapahit Empire.[1] In contrast to the heavy Indian influence in other art forms, the only obvious Indian influence in gamelan music is in the Javanese style of singing.[2]

In Javanese mythology, the gamelan was created by Sang Hyang Guru in Saka era 167 (c. AD 230), the god who ruled as king of all Java from a palace on the Maendra mountains in Medangkamulan (now Mount Lawu). He needed a signal to summon the gods, and thus invented the gong. For more complex messages, he invented two other Gongs, thus forming the original gamelan set.[3]
In the palaces of Java are the oldest known ensembles, the Munggang and Kodokngorek gamelans, apparently from the 12th century. These formed the basis of a "loud style."

A different, "soft style" developed out of the kemanak tradition and is related to the traditions of singing Javanese poetry, in a manner which is often believed to be similar to performance of modern bedhaya dance. In the 17th century, these loud and soft styles mixed, and to a large extent the variety of modern gamelan styles of Bali, Java, and Sunda resulted from different ways of mixing these elements. Thus, despite the seeming diversity of styles, many of the same theoretical concepts, instruments, and techniques are shared between the styles.[4]