The gong ageng (or gong gedhe in Ngoko Javanese, means large gong) is a musical instrument. It is the largest of the bronze gongs in the Javanese and Balinese gamelan orchestra and the only large gong that is called gong in Javanese. Unlike the more famous Chinese or Turkish tam-tams, Indonesian gongs have fixed, focused pitch, and are dissimilar to the familiar crash cymbal sound. It is circular, with a conical, tapering base of diameter smaller than gong face, with a protruding polished boss where it is struck by a padded mallet. Gongs with diameter as large as 135 centimeters (53 inches) have been created in the past, but gongs larger than about 80 centimeters (31 inches) are more common especially to suit the budget of educational institutions.
There is at least one large gong in each gamelan, but two are common and older gamelans may have three or more. The gong ageng usually has its own name, which may be bestow upon the entire set of instruments. The gong ageng is considered the most important instrument in a gamelan ensemble: the soul or spirit of the gamelan is said to live in the gong.Gong ageng are often proffered ritual offerings of flowers, food, and/or and incense before performances or each Thursday evening to appease spirits believed to live in and around it.
Tirtayasa (1631–1695), complete stylized name Sultan Ageng Tirtayasa, also known as Ageng and Abulfatah Agung, was the sultan of Banten (on Java in modern Indonesia) during the kingdom's golden age.
Ageng built a strong fleet on European models, which did considerable trade within the Indonesian archipelago, and, with help from the English, Danes, and Chinese, were able to trade with Persia, India, Siam, Vietnam, China, the Philippines, and Japan in the Javanese tradition of long-distance traders. This trade gave considerable wealth to Banten, the greatest period for which was arguably under Sultan Ageng Tirtayasa. In 1661 Ageng extended Banten rule to Landak in western Borneo. In the 1670s he also acquired Cirebon area following civil war in Mataram. Ageng established trade with Spanish Manila for silver and built canal for coconut palm and sugar plantations, among other developments.
Ageng was a strong opponent of the Dutch East India Company (VOC), and inevitably came into conflict with their headquarters at Batavia (modern Jakarta), 75 km to the east. In this sentiment Ageng also came into conflict with his son, the crown prince and later sultan Haji. Haji held considerable power in Banten, and was in favor of gaining support from the VOC. The court split into two factions, supporting the father and the son, and the more militant Muslim elite supported the father.