A metallophone usually an idiophone that consists of tuned metal bars which are struck to make sound, usually with a mallet. Metallophones can also include non-tuned instruments such as struck percussion idiophones as gongs and cymbals. Metallophones have been used in music in Asia for thousands of years.
Several different types of are used in both Balinese and Javanese Gamelan. They include the gendér, gangsa and saron. These instruments have a single row of bars that are tuned to the distinctive pelog or slendro scales, or a subset of them.
The Western glockenspiel and vibraphone are also metallophones as they have two rows of bars, in an imitation of the piano keyboard, and are tuned to the chromatic scale. In the Hornbostel-Sachs classification scheme they are categorized as a sub-category of “percussion plaques”.
111.22 Percussion plaques.