If a musical instrument has never been built before, how can you know what it will sound like? That’s the question UC Berkeley graduate student Cynthia Bruyns is answering with Vibration Lab, software she’s designing to simulate the sound of any percussive instrument, real or imagined, in a computer. Her system could someday enable musicians to play instruments that exist only on the screen, enable the interactive design of new physical instruments, and even boost the realism of immersive virtual environments for education and training.