Illumination is like a welcome sign. The potential buyer will feel a glowing warmth when you turn on all your lights for an evening inspection. Three's a crowd. Avoiding having too many people present during the inspections. The potential buyer will feel like an intruder and will hurry around the house.
Music is mellow.
But not when showing the house. Turn off the blaring radio or television. Let the salesman and buyer talk, free of disturbances. Keep them out of the way - Preferably out of the house. Be courteous but don't force conversation with the potential buyer.