Art has long been crucial to interior design, but today its role is often more mutable, and influential. Now a room might be designed around one piece, or a designer may commission an art installation along with a custom couch. An impressive art collection does not make a perfect interior, however: as always, it’s about striking a balance, selecting the right furniture, fabrics and finishes to complement what’s on the walls. Here are some rooms that represent the ideal union of fine art and interior design.