Percussion vessels consisting of a hollow object, usually of metal but in some cultures of hard clay, wood, or glass, which when struck emits a sound by the vibration of most of its mass; they are held in position at their vertex, the point farthest from their rim, and their zone of maximum vibration is towards the rim.
Source: Art & Architecture Thesaurus
http://vocab.getty.edu/page/aat/300041872
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