Guys at Asian Efficiency wrote a great piece on work music, where they reminded me of all the great sound tracks out there that are really good working music. It is inspiring and heart lifting, stimulating your inspiration, while not distracting you from the task at hand. Currently I am listening to the music from Steve Jablonsky, that was written for Transformers, and it puts me in a role of a person who is doing something incredibly important, in the terms of an epic historical event.
The emphasis of emotions is important for your workflow. And soundtracks are perfect for it.