Chelys

[1] According to the Homeric Hymn to Hermes, he came across a tortoise near the threshold of his mother's home and decided to hollow out the shell to make the soundbox of an instrument with seven strings.

[2] The word has been applied arbitrarily since classic times to various stringed instruments, some bowed and some plucked, probably owing to the back being much vaulted.

Numerous representations of the chelys lyre or testudo occur on Greek vases, in which the actual tortoiseshell is depicted.

[5] Modern experimental methods were employed, such as electronic speckle pattern laser interferometry and impulse response, to extract the vibrational behavior of the instrument and its main parts.

The experimental results validate the historical evidence that chelys was used in Greek antiquity as an accompaniment instrument to the human voice.

Cylix of Apollo with the chelys lyre, on a 5th-century BC drinking cup ( kylix )
Ancient Greek chelys or lyre from a drawing on a vase in the British Museum