A mansard or mansard roof (also called a French roof) refers to a style of hip roof characterized by two slopes on each of its four sides with the lower slope being much steeper, almost a vertical wall, while the upper slope, usually not visible from the ground, is usually pitched at the minimum needed to shed water. In more modern buildings, a mansard roof may mate a steep lower slope with a flat roof. (Wikipedia)

Why a song about a roof makes me want to dance silly is beyond me.

Vampire Weekend - Mansard Roof