Gamelan

A Gamelan is a musical ensemble from Indonesia, typically from the islands of Bali or Java, featuring a variety of instruments such as metallophones, xylophones, drums and gongs; bamboo flutes, bowed and plucked strings. Vocalists may also be included.
The term refers more to the set of instruments than to the players of those instruments. A Gamelan is a set of instruments as a distinct entity, built and tuned to stay together – instruments from different gamelan are generally not interchangeable.
The word Gamelan comes from the Javanese word gamels, meaning "to strike or hammer", and the suffix an, which makes the root a collective noun.
This instrument usually played during a traditional or religious event.

Below pictures of Gamelan taken at Jogja.


More detail at here.