This is a Beijing-to-Shanghai collaboration between Beijing rapper YK (aka Young Kin) and Shanghai rapper Young Cee. Young Kin is a very well known Beijing rapper, probably one of the best in Beijing and all of China. I'm not too sure about Young Cee, but he sounds pretty dope as well.
This song, 夜上海 is about Shanghai nightlife. The funky beat was sampled from the original 夜上海 by Zhou Xuan which is considered a Chinese classic. The original song has a similar feel to Frank Sinatra's New York, New York. That song was made during the time when jazz music from America was THE SHIT in Shanghai.
And just in case if you aren't aware, Shanghai is busily preparing for the 2010 World Expo, which is probably why Young Kin and Young Cee remade the song to give their big ups to Shanghai. The music video was directed by Stanley Yang who grew up in Vancouver but is now based in Shanghai.