How loud is too loud?

This is the age old question...How loud is too loud? Only it is not the parent complaining this time...it's the brother. They are sitting at the breakfast table eating...Danny is listening to the cd his dad took out of the library for him. It has "Living on a Prayer" (Bon Jovi) from Rock Band 2, one of Danny's favorite songs of the moment. Danny needs to blast it. He has already blasted it once, before Alex came into the room. Alex is trying to read while eating. I figure, if I can hear it loud and clear while on the computer (on another floor)...it's too loud. Let poor Alex, who is not really a fan of music, have a little peace. He didn't make Danny turn it down unreasonably. I can still hear it. Danny...Just deal with it this time...OK Danny...Now that "Dead or Alive" (from Rock Band 1) is done...just finish up and get ready for school...