What is the relationship between Jay Chou and CoCo Lee?

Cooperative friends. Jay Chou once wrote a song for CoCo Lee. 20011kloc-0/3, CoCo Lee released the album "Promise", including a song named "Beijing Opera Blues". This song was written by Jay Chou, written by Fang Gang and sung by Jay Chou. CoCo Lee was born in 1975 and Jay Chou was born in 1979. The age gap between them is not that big. There is no generation gap, frequent cooperation and good interpersonal relationship.