qin; guqin; seven-stringed Chinese zither
Refers specifically to the Chinese seven-stringed zither (guqin). It is colloquial, but in Japanese it is a straightforward descriptive term. Compare with 琴 (きん), which can refer to the same instrument in a more traditional or classical context.
See also: 琴 (きん)
He is learning to play the guqin.
The qin is a traditional Chinese musical instrument.