The Glong Khaek or the Glong Koo is a pair of double-face leather drums. The drum that produces the higher pitch is called the Glong Khaek Tua Poo (the male drum), while the other drum that produces the lower pitch is called the Glong Khaek Tua Mia (the female drum).
         It is assumed to have originated in Java island of Indonesia. Formerly, they were played in an ensemble with the Pii Chawa, called the “Pii Chawa-Glong Khaek ensemble”. The ensemble was used to lead the royal processions, both by land and water. It is also played in accompaniment with the traditional martial arts performances or even in the Bua Loi or Pii Pat Nanghong ensembles, which are played in funeral ceremonies.
         The Glong Khaek has three main component parts.
         1. The body of the drum is made of hard wood for the good quality of sound, beauty and appropriate weight. The kinds of wood that are usually used to produce the drum are rosewood, Burmese ebony and Grapee Khao-kwaai.
         The body of the drum is in cylindrical shape. The faces are of different sizes.
         The large face is called “Naa Rui” (หน้ารุ่ย), while the small face is called “Naa Taan” (หน้าต่าน). The interior body of the drum is hollow to function as the sound box.
         2. The Nang Riad, the tensioning cords were formerly made of rattan strips, but presently are made of cow hide or buffalo hide strips. Its function is to pull and stretch the two faces of the drum to tense up the leather faces. It can be adjusted to increase or lower the pitches as desired.
         There is another cord tying across the Nang Riad to tidy up the Nang Riad. It is called “Rad-ok”.
         3. The faces of the drum are made of goat skin, processed with scraping, sun-drying, kneading, etc. until it is in the desired condition. Then the leather is stretched over the faces of the drums and tensioned with the Nang Riad.
         The Glong Khaek must be played in a pair, so it needs 2 drummers. Each drummer places the drum on his lap and beats it with both hands alternately according to the rhythmic style of the song which is called “Naa Tub”. At present the Glong Khaek is usually played in the Pii Pat ensemble replacing the Tapone and the Glong Song-naa.