Jay-Z -- I Refuse to Clap for Chris Brown

It was the standout performance of the MTV VMAs -- Chris Brown dancing his face off -- but while everyone from Kanye to Bieber stood up and cheered ... Jay-Z refused to even crack a smile.

Of course, Jay is the man who discovered Rihanna -- and they're still VERY tight. So, was his decision to NOT clap a message to Brown? Or is Jay simply too cool for the room?