This matrix represents the most profitable and influential popular music albums of all time. The "X" axis represents how influential an album is considered to be. The "Y" axis represents total sales. The few albums that are BOTH popular and influential occupy a very privileged position. Note that the colored border around each album represents what year the album was introduced. The colors are red-shifted, that is, the more redder/brown the color is the older the album is. The more violet, the more recent the album is.