The guan (Chinese: 管; pinyin: guǎn; lit. 'pipe" or "tube"') is a Chinese double reed wind instrument. The northern Chinese version is called guanzi (管子) or bili (traditional: 篳篥; simplified: 筚篥) and the Cantonese version is called houguan (喉管). It is classified as a bamboo instrument in the Ba Yin (ancient Chinese instrument classification) system. Unlike other instruments in the double-reed family of woodwinds which mostly have conical bores, such as the Chinese suona or the Western oboe, the guan has a cylindrical bore, giving its distinctive mellow, yet piercing buzz-like timbre. Source: Wikipedia (en)