sentence: Sounds are produced by  open strings, stopped strings, and harmonics.
sentences_after: By tradition the qin originally had five strings, but ancient qin-like instruments with 10 or more strings have been found. The modern form has been standardized from about two thousand years.
concept_name: sound
headings: Guqin
categories: Plucked string instruments Music in China Masterpieces of the Oral and Intangible Heritage of Humanity