I often somewhat jokingly say that focus is over rated. Sure super-sharp, crystal clear photos are great for entering in competitions. But there are times when blurs enhance the mood and help tell a story. The examples below are of a band called McTuff here in Seattle, featuring Joe Doria on Hammond Organ. Static shots of the players are nice, but by introducing some motion blur and defocusing of the lens I think you get more of the emotion to be captured in the image.