information:extraction, linguistic:paraphrasing
Classification

Percussion instruments are classified by various criteria sometimes depending on their construction, ethnic origin, function within musical theory and orchestration, or their relative prevalence in common knowledge.

The word percussion derives from the Latin verb percussio to beat, strike in the musical sense, and the noun percussus, a beating. As a noun in contemporary English, Wiktionary describes it as the collision of two bodies to produce a sound. The term is not unique to music, but has application in medicine and weaponry, as in percussion cap. However, all known uses of percussion appear to share a similar lineage beginning with the original Latin percussus. In a musical context then, the percussion instruments may have been originally coined to describe a family of musical instruments including drums, rattles, metal plates, or blocks that musicians beat or struck to produce sound.

The Hornbostel–Sachs system has no high-level section for percussion. Most percussion instruments as the term is normally understood are classified as idiophones and membranophones. However the term percussion is instead used at lower-levels of the Hornbostel–Sachs hierarchy, including to identify instruments struck with either a non sonorous object hand, stick, striker or against a non-sonorous object human body, the ground. This is opposed to concussion, which refers to instruments with two or more complementary sonorous parts that strike against each other and other meanings. For example:

111.1 Concussion idiophones or clappers, played in pairs and beaten against each other, such as zills and clapsticks.

111.2 Percussion idiophones, includes many percussion instruments played with the hand or by a percussion mallet, such as the hang, gongs and the xylophone, but not drums and only some cymbals.

21 Struck drums, includes most types of drum, such as the timpani, snare drum, and tom-tom.

412.12 Percussion reeds, a class of wind instrument unrelated to percussion in the more common sense

There are many instruments that have some claim to being percussion, but are classified otherwise:

Percussion instruments are sometimes classified as pitched or unpitched. While valid, this classification is widely seen as inadequate. Rather, it may be more informative to describe percussion instruments in regards to one or more of the following four paradigms: