I would think the loud noise could be stressful. Think about the thump, thumping of deep base. Loud noises or music could cause vibrations, which might be felt in the tank. Also if there is a lot of different activity in the area around the tank(that part of the room being used more, a lot of people coming and going near the tank etc), the movement might be stressing or scaring the fish some too. Hopefully your tangs will be alright..