The oldest East Slavic multi-string plucked instrument, belonging to the zither family due to its strings being parallel to its resonance board. It may have a connection to the Byzantine form of the Greek kythare, which in turn derived from the ancient lyre, or might have been imported from Western and Central Europe during the Middle Ages when the zither had immense popularity. It has its relatives in Europe and throughout the world, including kantele (Finland), langeleik (Norway), zither, psaltery, qanun (Arabic world), autoharp, zheng (China) and koto (Japan). In Ukraine, it is thought that the gusli may have influenced the development of the multi-stringed bandura, which largely replaced it in the 19th century.
 
Folk gusli have from 11 to 36 gut or metal strings, tuned diatonically.