Wikipedia
The cümbüş (; ) is a Turkish stringed instrument of relatively modern origin. It was developed in 1930 by Zeynel Abidin Cümbüş (1881–1947) as an oud-like instrument that could be heard as part of a larger ensemble.
The cümbüş is shaped like an American banjo, with a spun-aluminum resonator bowl and skin soundboard. Although originally configured as an oud, the instrument has been converted to other instruments by attaching a different set of neck and strings. The standard cümbüş is fretless, but guitar, mandolin and ukulele versions have fretboards. The neck is adjustable, allowing the musician to change the angle of the neck to its strings by turning a screw. One model is made with a wooden resonator bowl, with the effect of a less tinny, softer sound.