Virtual Reality (VR) and digital fabrication technologies today are ushering in a new wave of opportunities in instrument design; the marriage of these two domains, seemingly at odds with each other, can bring impossible instruments to life. In this article, the authors first sample such instruments throughout history. The authors also look at how technology has facilitated the materialization of impossible instruments from the twentieth century on. They then discuss the bridging of VR and fabrication as a new frontier in instrument design, where synthetic sounds can be used to condition an equally synthetic sensory scaffolding upon which the time-varying spectra can be interactively anchored: The result is new instruments that can defy our sense of audiovisual reality while satisfying our proprioceptive and haptic expectations. The authors report on their ongoing work as well as their projections of how emerging technologies in VR and fabrication will shape the design of new musical interfaces.