Hand-held clappers are among a vast and varied category of 'self-sounding' musical instruments, known collectively as idiophones, that produce sound without the addition of a stretched membrane or a vibrating string or reed. The most common form of clapper in the Benin corpus consists of a cylindrical shaft surmounted by the figure of a long-beaked bird with outstretched wings, such as this example. They are played by striking the bird figure on its beak with a metal rod. The bird perched with outstretched wings on the finials of this idiophone sounded on the occasions of Ugie Oro court festivals is usually called the "bird of prophecy" (ahianmwen-oro) and sometimes the "messenger of god" (odibosa). Beginning with the reign of King Esigie in the sixteenth century, the sounding of clappers depicting the bird of prophecy at Ugie Oro court ceremonies was regarded as a sign that the kings of Benin were endowed with the power to alter history.