IDIOPHONES – from Wikipedia

An idiophone is any musical instrument which creates sound primarily by way of the instrument vibrating itself, without the use of strings or membranes. It is one of the four main divisions in the original Hornbostel-Sachs scheme of musical instrument classification. Idiophones are probably the oldest type of musical instrument (not counting the human voice). In the early classification of Victor-Charles Mahillon, this group of instruments was called autophones.

Most percussion instruments which are not drums are idiophones. Hornbostel-Sachs divides idiophones into four main sub-categories. The first division is the struck idiophones (sometimes called concussion idiophones). This includes most of the non-drum percussion instruments familiar in the west. They include all idiophones which are made to vibrate by being hit, either directly with a stick or hand (like the wood block, singing bowl, triangle or marimba), or indirectly, by way of a scraping or shaking motion (like maracas or flexatone). Various types of bells fall into both categories.

The other three sub-divisions are rarer. They are plucked idiophones, such as the jew's harp, amplified cactus, music box or mbira (thumb piano); blown idiophones, of which there are a very small number of examples, the Aeolsklavier being one; and friction idiophones, such as the singing bowl, glass harmonica, glass harp, turntable, verrophone, daxophone, styrophone, musical saw, or nail violin (a number of pieces of metal or wood rubbed with a bow).

A number of idiophones that are normally struck, such as vibraphone bars and cymbals, can also be bowed.

Mallet-struck tuned percussion

A number of instruments fall into a sub-class within this group, and relate directly to the classification, tuned percussion. They are struck with mallets or with sticks.

They include:

marimbas

xylophones

vibraphones

glockenspiel

balafons

steelpan

celesta, a keyboard-operated idiophone