Origins, cultural significance or tradition, for example grouping instruments as Latin percussion or as African drums. This criterion overlaps but is not a subset of the usage criterion; Both Latin percussion and African drums also refer to some extent to current usage.
Percussion instruments vary enormously in nature and usage, and have possibly the longest history of any group of musical instruments.[1] For these and other reasons their classification proves difficult, and different classification systems are used in different contexts.
At the highest level of grouping, authorities differ over whether stringed instruments such as the hammered dulcimer and keyboard instruments such as the celesta are percussion instruments, let alone the piano which is both stringed and a keyboard and yet sometimes also termed percussion.[2][3]
Hornbostel–Sachs does not use the term percussion as a general grouping at all, but instead in a very different sense to the common usage. Instruments such as castanets and cymbals used in pairs are not percussion in the Hornbostel–Sachs sense, but are percussion instruments in every other sense.
Similar problems are encountered at lower levels of classification.
^http://pianoeducation.org/pnopnfaq.html retrieved 22 March 2012 The piano is really a "hybrid"--a combination of two types. It's a string instrument because the musical tones originate in the strings; and it's also a percussion instrument, because the strings are set into vibration by being struck with hammers. To be historically correct, it's classified as a "keyed zither" by musicologists.
^"Is the Piano a Percussion Instrument?". Archived from the original on 2012-04-19. Retrieved 2012-03-22. retrieved 22 March 2012: How you class the piano depends on which of the following classification schemes you feel is most relevant: (1) By how the sound is produced. By one thing striking another (percussion), by plucking or bowing (strings), or by vibrating a column of air (wind). (2) By construction. If you can’t make the sound without the strings, then call it a stringed instrument. (3) By method of playing. If you use a keyboard, it’s a keyboard instrument; if you hit it with a stick, it’s a percussion instrument. Traditionally, the first classification scheme has held sway. Number 2 is not widely accepted. But Number 3 is gaining ground. For now, most musicologists would agree, the piano is a percussion instrument, and also a keyboard instrument.