Pitched percussion instrument

A pitched percussion instrument is a percussion instrument used to produce musical notes of one or more pitches, as opposed to an unpitched percussion instrument which is used to produce sounds of indefinite pitch.
Pitching of percussion instruments is achieved through a variety of means.

Membranophones are tuned by altering the surface tension of the face that is struck.
Idiophones gain their pitch through the physical characteristics of each respective bar.

The term pitched percussion is now preferred to the traditional term tuned percussion:

Many untuned percussion instruments are tuned by the player, but this tuning does not relate to a particular pitch.
Untuned percussion instruments can and frequently do make sounds that could be used as pitched notes in an appropriate context.

This second consideration also means that the traditional division into tuned and untuned percussion is to some extent oversimplified:

Some percussion instruments are almost always used as pitched percussion.
Some percussion instruments are sometimes used as pitched percussion and, at other times, as unpitched percussion.
Some percussion instruments are almost always used as unpitched percussion.

Pitched percussion includes the class of: