CASTANETS (Fr. castagnettes, Ger. Kastagnetten, Span. castañuelas), instruments of percussion, introduced through the Moors by way of Spain into Europe from the East, used for marking the rhythm in dancing. Castanets, always used in pairs, one in each hand, consist of two pear or mussel-shaped bowls of hard wood, hinged together by a silk cord, the loop being passed over the thumb and first finger. The two halves are then struck against each other by the other fingers in single, double or triple beats, giving out series of hollow clicks of indefinite musical pitch. When intended for use in the orchestra the pair of castanets is mounted one at each end of a wooden stick about 8 in. long, which facilitates the playing. Castanets are also sometimes used in military bands and are then specially constructed. The two halves are kept open by a slight spring fixed to a frame attached to the hoop of a side drum, and the instrument is worked by the drummer with an ordinary drumstick. An instance of the use of castanets in opera occurs in the Habanera in Carmen. A quaint description of castinatts is given in Harleian MS. 2034 (f. 208) at the British Museum (before 1688) with a pencil sketch which tallies very well with the above. The MS. is by Randle Holme and forms part of the Academy of Armoury. Castanets (κρόταλα) were used by the ancient Greeks, and also by the Romans (Lat. crotalum, crotala) to accompany the dances in the Dionysiac and Bacchanalian rites.