Gasu (pinyin: gā suo), alias Layindi, is a musical instrument of the Miao people, popular in Xilin, Napo and other places in Guangxi Zhuang Autonomous Region.

The sound of the flat blow is soft and the sound of the super blow is crisp. Playing techniques such as finger sliding and wiping holes are often used, and its portamento has a unique flavor. It is a wind instrument that is deeply loved by the Miao people and is mostly used for solo entertainment.

The music includes "Drinking Tunes" and "Pain Tunes".