Walls are stupid. We need a roof over our head, to keep the rain off, and we need a floor under our feet to keep us out of the grot, but for what do we need walls? For this: spendy Scandi sound-maker Bang & Olufsen has revealed BeoSound Shape, a wall-mounted wireless hi-fi system that you build by tessallating a mixture of hexagonal tiles. Some of them have amplifiers, some are speakers and the rest are stuffed with acoustic dampening material, although one must also contain the BeoSound Core wireless module - AirPlay, Chromecast, Spotify, Wi-Fi, Bluetooth. How much? B&O isn't saying yet, except that a basic system of six tiles will cost about £3400. Yipes.