Other mistake: The outside shots show that the house is in the middle of a row of houses, connected to other houses on both sides. But in the living room, behind the stairs, is a window looking outside. There couldn't possibly be a window there as that is where the house shares a wall with the house next door.
Revealing mistake: Everytime someone opens the front door to go outside there is just steps leading outside, but when they are on the steps outside and the doors to the inside are open there is a wall and a table with a lamp. Inside that is not there.
Chosen answer: That is the song "Open the Door Richard."