Until recently, tuning keys similar to the present example were simply described as decorative objects, their exact purpose unknown. For a discussion of the excavation of the 5th century B.C. tomb of the Marquis Yi of Zeng, 1977-78, and the discovery of a horde of musical instruments including a ten-stringed zither with tuning pegs on the interior which would have necessitated the use of a tuning key, such as the present example, see J. So, 'Different Tunes, Different Strings: Court and Chamber Music in Ancient China', Orientations, May 2000, pp. 26-34. The author notes that the first indication of the use of these objects was the excavation of tuning keys together with matching tuning pegs from a Han dynasty tomb in 1983.
A similar tuning key surmounted by a bear with a slit in its back from the collection of Dr. Paul Singer is illustrated by M. Loehr, Relics of Ancient China, Asia Society, New York, 1965, no. 112; and one is illustrated in Sammlung Baron Eduard von der Heydt, Wien, 1936, no. 103. Another similar example raised on one hand of a bronze acrobat, which must have served as an amusing stand for the tuning key, in the collection of the Freer Gallery of Art, is illustrated in Chinese Art of the Warring States Period, 1982, p. 80.