Castanets, also known as "Spanish castanets", are mostly used in the folk dances of southern European countries such as Spain, Italy and Latin America. In symphonic, operatic and dancefloor music, castanets are usually limited to southern European and Latin American styles. Sometimes, castanets can even be used for solos. 
There are two kinds of castanets: one used by dancers to accompany them, and the other by a symphony orchestra. Castanets were also introduced to Europe from the east and mainly became a true folk instrument of the Spanish song and dance. In the symphony orchestra, they were first used in music of the nature of Spanish dance, such as the morning song of the clown and the bolero.