I have to agree with Jake here. I was one of the people that though entertainment during modeling and all that helps me relax, puts me in the mood. You may find yourself doing a lot of work while listening to music, you will also have a lot of fun... but that's just because you have a lot of time on your hands and something is bound to come out of your hours in front of the computer. This article is more about what you can do when you don't have a lot of time. Everything that distracts you, even the music is bad for your workflow.
Don't like to promote the Speed Modeling everywhere I post something
but that's the place where I realized this. If I speed model I close everything... I even tell my girlfriend I'm speed modeling (she knows what this means) and I do what I plan fast and professional (well... that's what I like to think). Try modeling something in 60min while chatting with a few people, listening to some music and surfing the web. You won't get anything done in time. Then try it unplugged, you'll notice the difference. When you have the whole day ahead of you it's hard to see you lose time but you do.