張衛健
The Big Four is an all-male Hong Kong musical group formed by Dicky Cheung, Andy Hui, William So, and Edmond Leung in 2009. They released their first self-titled single in 2009, in which the single topped most of Hong Kong's music charts. Their next single, "Unable to Love" (愛莫能助) in 2010, was also topped charts and received consistent airplay for many weeks.