Most of the music we are playing today is drawn from the traditional repertoire of Central Java and Bali. Each instrument in the gamelan has a definite role; some of the instruments only play the central melody of the piece, the balungan. Other instruments have the job of elaborating this melody with faster and/or higher notes, whilst another group of instruments, lower in pitch and slower moving, mark the rhythmic structure of the piece. A special importance is given to the 'big gong', as it is affectionately known; this slowest-moving of all the instruments is one of the most important, marking as it does the endings of melodic sections and entire pieces. Also important are the drums, which set the tempo and give signals to the players, functioning almost as a conductor.
Although the tradition of gamelan stretches back thousands of years, it is far from being a dead art-form. Gamelan music has spread all over the world, having an important influence on many Western classical composers. New music is being written for the gamelan all the time by members of the Naga Mas group, some of it drawing on traditional styles and some of it developing in new directions. This spirit of openness and experimentation is very much in accord with the approach to gamelan taken by the Javanese themselves.