The angklung is a musical instrument made of bamboo tubes attached to a bamboo frame. The tubes are carved so that they have a resonant pitch when struck. The two tubes are tuned to octaves. The base of the frame is held with one hand while the other hand shakes the instrument rapidly from side to side; this causes a rapidly repeating note to sound. Thus each of three or more angklung performers in an ensemble will play just one note and together complete melodies are produced.