What is "kolitong"

A Kolitong is a bamboo polychordal tube zither from Bontok, Kalinga, Philippines with six strings that run parallel to its tube body. The strings are numbered from one to six, from lowest to highest pitch. The body acts as the instrument's resonator. The body may be a whole tube or a half tube, in both cases the two ends of the body are closed by the bamboo nodes. To help with the resonance of the instrument, holes are made on both nodes and long cracks are made along the body parallel to the strings. In the Kalinga group, men play the Kolitong at night as a solo instrument. A variety of bamboo tube zithers are found throughout the Philippine archipelago, each zither differing from the other in name, size, and design depending on its associated ethnic group.