FEN is an improvised music quartet. Comprising Otomo Yoshihide (Japan), Yuen Chee Wai (Singapore), Yan Jun (China) and Ryu Hankil (Korea), it was formed in 2008 in Marseille.

The initial intent of forming FEN was not based on a particular pursuit of any specific form of musical aesthetic, but rather to develop and deepen the improvised music networks of Asia. This desire was furthered by these 4 individuals, each with their individual endeavours to organise music-related activities and bridge communication, using a kind of improvisational music vernacular to connect one another. Within the quartet, and beyond, FEN strives for a collaboration that is direct and non-dominant based, while achieving a musical flow that is fluid and symbiotic.

Concurrently, the 4 members are active contributors in the fields of experimental, improvised, computer and electronic music, visual art, performance, literary, curatorial and publication fields. Their creative work is strongly reinforced within the idea of networks and genealogy.

The music of FEN has been described as a combination of noise, random occurrences, rock, free jazz and the likes, in an improvisational rigour without any prior communicated agreement. Each member is free to change and choose their musical instrument and methodology of performance.

FEN has toured Japan, China and Europe, and has played festivals in North America, UK, Korea and Singapore. In 2018, FEN collaborated with Singaporean artist Ho Tzu Nyen for a new work in the Gwangju Biennale. FEN have also been commissioned for a new work with NeoN ensemble for Borealis Festival 2020.