The gong ageng (or gong gedhe in Ngoko Javanese, means large gong) is an Indonesian musical instrument used in the Javanese gamelan. 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.[1] Unlike the more famous Chinese or Turkish tam-tams, Indonesian gongs have fixed, focused pitch, and are dissimilar to the familiar puke 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.[2]
There is at least one large gong in each gamelan, but two are common and older gamelans may have three or more.[1] The gong ageng usually has its own name, which may be bestow upon the entire set of instruments.[1] 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.[3] Gong ageng are often proffered ritual offerings of flowers, food, and/or and incense before performances[4] or each Thursday evening[1] to appease spirits believed to live in and around it.
Commonly, less expensive iron gong ageng or a slit-type gong are made to fulfill the role of the bronze gong, though at the loss of sound quality- for poorer regions and villages.[2] The cost of expertly pure cast & beaten bronze has seen a rise in bronze-plated and bronze-laminated iron gongs created for the undiscerning expatriate.