A coin of one euro is preforming[read_more] a piece of Bach by rolling down a metallophone, eventually ending up in the return tray. The Money Back Guarantee series wants to provide an insight; where money originally purely was used as a means of exchange, money nowadays has been become a goal in itself. A mean to express prosperity and splendour. This project wants to emphasize that money should retain its original function as a medium of exchange. An instrument.