When I'm working on the PC I'm working. Except when I'm bludging. I'm a programmer, it's what I'm paid to do. At least, I would be paid to do it if my company was making money, but that's beside the point. Yes, taking a break from it would interrupt my concentration, but then that's kinda the point about taking a break. I plan for that, and if I don't feel like doing it then I don't have to do it right now. CD swapping is an unplanned activity. The way my brain works is that I actually need something to block out while I'm thinking about things. If it's too quiet I get bored and can't concentrate at all. If it's got to be really intense then I'll turn the music off for a bit, but I can't concentrate like that for very long.