Looking for some suggestions of music that isn't distracting. What unobtrusive music to put on to help concentrate? Or do you need no music at all to focus your mind?

Currently listening to Trentemøller (is minimal techno the way to go? I wonder if this is part of the reason for the success of more ambient music?) and had this instrumental playlist on this morning http://songsfortheboywhowouldntreadrilke.blogspot.com/2010/01/instrumental-asylum.html and the one I made beneath it.