<Table> <Tr> <Td> </Td> <Td> This article includes a list of references, but its sources remain unclear because it has insufficient inline citations . Please help to improve this article by introducing more precise citations . (March 2015) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article includes a list of references, but its sources remain unclear because it has insufficient inline citations . Please help to improve this article by introducing more precise citations . (March 2015) (Learn how and when to remove this template message) </Td> </Tr> <P> A percussion instrument is a musical instrument that is sounded by being struck or scraped by a beater (including attached or enclosed beaters or rattles); struck, scraped or rubbed by hand; or struck against another similar instrument . The percussion family is believed to include the oldest musical instruments, following the human voice . </P> <P> The percussion section of an orchestra most commonly contains instruments such as timpani, snare drum, bass drum, cymbals, triangle and tambourine . However, the section can also contain non-percussive instruments, such as whistles and sirens, or a blown conch shell . Percussive techniques can also be applied to the human body, as in body percussion . On the other hand, keyboard instruments, such as the celesta, are not normally part of the percussion section, but keyboard percussion instruments such as the glockenspiel and xylophone (which do not have piano keyboards) are included . </P>

What makes a percussion instrument a percussion instrument
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