Wikipedia
The paldong is a traditional lip-valley flute of the Kalinga tribes in the Philippines. The paldong is made of bamboo. Its upper edge is cut away obliquely from the backside, and then cut away slightly from the frontside. The player's lower lip is placed against the cut away surface. The paldong is open at both ends, with a total of four finger holes; three in front, one at the back.
The melodies played on the lip-valley flute are mostly improvisatory. When given titles, the titles describe what the music is trying to simulate such as the chirping of a bird, the cry of an eagle, the buzz of a wasp, etc. It is a solo instrument usually used by men for serenades or courting women, or merely for leisure and to pass the time away.