Instruments that produce sound from the substance of the instrument itself (wood or metal) are classified as idiophones. They are further divided into those that are struck, scraped, plucked, shaken, or rubbed. In the Philippines, there are metal and wooden (principally bamboo) idiophones.
Metal idiophones are of two categories: flat gongs and bossed gongs,. Flat gongs made of bronze, brass, or iron are found principally in the north among the Isneg, Tingguian, Kalinga, Bontok, Ibaloi, Gaddang, Ifugao, and Ilonggot. They are commonly referred to as gangsa. The gongs vary in size, the average are struck with wooden sticks, padded wooden sticks, or slapped with the palm of the hand. Gong playing among the Cordillera highlanders is an integral part of peace pact gatherings, marriages, prestige ceremonies, feasts or rituals.
In Southern Philippines, gongs have a central profusion or knot, hence the term bossed gongs. They are of three types: 1) sets of graduated gongs laid in a row, called kulintang or kulintangan 2) larger, deep-rimmed gongs with sides that are turned in called agong, 3) gongs with narrower rims and less prominent bosses called gandingan. These gongs maybe played alone but are often combined with other instruments to form various types of ensemble.
Bamboo idiophones abound in the Philippines- xylophones. drums, quill-shaped tubes, stamping tube, scrappers, buzzers and clappers. The bamboo xylophone gabbang is found in the Southern Philippines among the Yakan, Sama, Tausug, and Palawan. It consist of bamboo keys of graduated lengths mounted on a trapezoidal box. The number of keys varies among the different tribes, ranging from 3 to 22 cm. In Northern Luzon among the Kalinga, individual xylophone-like blades called patatag are struck with bamboo sticks. The bamboo slit drums such as the Bukidnon bantula is fashioned out of a bamboo tube closed at both ends with anode with a slit cut out of the tube. Found among the different groups of people, its main use is to announce important events.
The struck quilt-shape bamboo tubes with notches etched on the tube, are found only in the southern Philippines such as the Maranao tagutok and the Maguindanao kagul. The player scrapes the notches with a bamboo stick.
Among the Cordillera highlanders, bamboo buzzers are widespread. They are made from a length of bamboo closed with a node at the bottom with its top half shaped so that two tongues face each other. The top half is struck against the palm of the hand. They are known by different names such as, balingbing, pew-pew, pakkung, bilbil, bungkaka by the various groups.
The Ifugao have a bamboo clapper, hanger, fashioned from a tubular section of bamboo, split from one end to approximately half of the tube. Each half of the split portion is shaped to make it narrower in the middle, thus making it more flexible when the halves are made to flap against each other.
Wooden idiophones include sticks, suspended logs and log drums. The Hanunuo kalutang, consist of pair of sticks cut from forest trees. These are struck against each other and played while hiking through forest and mountain trails.
The Ifugao pattung, is a percussion yoke bar made from a tapered piece of wood and struck with a stick. It is used for ceremonies for the sick, at rites which entail the offering of sacrificial pigs, or at death rituals.
Suspended logs are widespread in the Southern Philippines where they are known by different tribes. The Maguindanao luntang, consists of logs of varying lengths hung in order from longest to shortest. The pointed playing ends of each log is struck by one performer creating a melody against which another performer beats drone rhythm on one of the logs.
The Tagakaolo edel is a sounding board with a resonator played during wedding celebrations together with a drum or gong to accompany dancers. The Bagobo and Bilaan have similar drums.
Jaw harp are abound all over the Philippines. They are principally made from bamboo although in the Philippines, some are made of metal. It is a type of mouth resonated instrument consisting of a flexible tongue fixed at one end to a surrounding frame. The player places the free end of the instrument with the hand, or in some other types by pulling a string attached to the blade. The instruments have different names among the various tribes . In the south the most common term is kubing; in Palawan, western Philippines it is called subing, in the north ulibaw.
Above, stamps of kulintagan and subing issued in 1968