Percussion instruments can be, and indeed are, classified by various criteria
sometimes depending on their construction, ethnic origin, their function
within musical theory and orchestration, or their relative prevalence in
common knowledge. It is not sufficient to describe percussion instruments
as being either "pitched" or "unpitched" which is often
a tendency; rather it may be more informative to describe percussion instruments
in regards to one or more of the following four paradigms:
- Idiophones produce sound when their bodes are caused to vibrate.
- Most objects commonly known as "drums" are
membranophones. "Membranophones produce sound when the membrane
or head is put into motion.
- Most instruments known as "chordophones" are defined as string
instruments, but some such as these examples are, arguably, percussion
- Most instruments known as "aerophones" are defined as wind
instruments such as a saxophone whereby
sound is produced by a person or thing blowing air through the object.
However, the following example instruments, if played at all in a musical
context, are played by the percussionists in an ensemble.
- Electrophones are also percussion instruments. In the strictest sense,
all electrophones require a loudspeaker (an idiophone or
some other means to push air and create sound waves). This, if
for no other argument, is sufficient to assign electrophones to the percussion
family. Moreover, many composers have used the following example instruments
and they are most often performed by percussionists in an ensemble.
It is in this paradigm that it is useful to define percussion instruments
as either having definite pitch or indefinite pitch. For example, some instruments
such as the marimba and timpani produce an obvious fundamental pitch and
can therefore play melody and serve harmonic functions in music while other
instruments such as crash cymbals and snare drums produce sounds with such
complex overtones and a wide range of prominent frequencies that no pitch