kithara or cithara, musical instrument of the ancient Greeks. It was a plucked instrument, a larger and stronger form of the lyre, used by professional musicians both for solo playing and for the accompaniment of poetry and song. It consisted of a relatively square wooden box that extended at one end into heavy arms. Originally it had 5 strings, but later there were 7 and finally 11 strings. These were stretched from the sound box across a bridge and up to a crossbar fastened to the arms. Since the strings were of equal length, tuning was determined only by the thickness and tension of each string. Because of its size and weight, it rested against the body of the player and was held in position by a band. The player usually stood when performing.

Large lyre of Classical antiquity, the principal stringed instrument of the Greeks and later of the Romans. It had a box-shaped resonating body from which extended two parallel arms connected by a crossbar to which 3–12 strings were attached. It was held vertically and plucked with a plectrum; the left hand was used to stop and damp the strings. It was played by singers of the Greek epics, as well as by later professional accompanists and soloists.

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