Did Jay Chou sing duets?

A lot.

Happy birthday to me.

Coral Sea

Thousands of miles away

Butterfly Ji

Prague square

Chivalry

There is also a song that everyone is not very clear about.

Fortune-telling, sung with Jacky Cheung, is included in Jacky Cheung's hit album.

Wen Lan choir on the roof.

Prague Square and Jolin Tsai Choir

Jay sang the pirate rap part.

Brusven Li, a Peking Opera, is also a rap part.

In addition to this guy's answer, there are

Draw sand

smirk

It's a supplement. ...