Rare musical instruments can tug at the heart strings of affluent, culturally savvy collectors in a way stock certificates or luxury property never will. Take, for example, Le Silex, a piano developed by UK-based Edelweiss Pianos. It’s a one-in-a-billion musical masterpiece—quite literally, as only seven will ever be produced. As much a work of art as a musical instrument, its design is inspired by the beauty of weathered flint. Each piano is cast from a life-size clay rendering meticulously sculpted by a team of 15 designers and artisans, and takes six months to complete. Edelweiss offers a variety of design options, including hand-painted textures and tactile finishes, to make each piano unique. The instrument not only looks good, it sounds good— whether you play or not. An iPod built into a hidden drawer and a self-playing mechanism allows the piano to play along with pre-recorded tracks, from classical and jazz to country and pop.