This chapter focuses on one of the most abundant metals in the earth’s crust: aluminum—an extremely light and brightly shimmering material that has become iconic for the modern music industry. Besides its well-known use for compact discs, it has also been used in violin and keyboard making. Instrument makers in the United States and Germany, in particular, developed several methods to replace the wood traditionally used for these instruments with this light metal. Taking a closer look at the production of specific violins and keyboard instruments from American and German collections, this chapter highlights the immense energy consumption required to extract and process aluminum. How did this energy balance affect the aesthetics of aluminum instruments and their significance for music history?