Castanets are a percussion instrument, much used in Moorish, Spanish, Portuguese and Latin American music. The instrument consists of a pair of concave shells joined on one edge by string. These are held in the hand and used to produce clicks for rhythmic accents or a ripping or rattling sound consisting of a rapid series of clicks. They are traditionally made of hardwood, although these are plastic.
In practice a player usually uses two pairs of castanets. One pair is held in each hand, with the string hooked over the thumb and the castanets resting on the palm with the fingers bent over to support the other side. Each pair will make a sound of a slightly different pitch. The higher pair, known as hembra (female), is usually held in the right hand, with the larger macho (male) pair held in the left.