Digital musical instruments bring new possibilities for musical performance.They are also more complex for the audience to understand, due to the diversityof their components and the magical aspect of the musicians' actions whencompared to acoustic instruments. This complexity results in a loss of livenessand possibly a poor experience for the audience. Our approach, called Rouages,is based on a mixed-reality display system and a 3D visualization application.It reveals the mechanisms of digital musical instruments by amplifyingmusicians' gestures with virtual extensions of the sensors, by representingthe sound components with 3D shapes and specific behaviors and by showing theimpact ofmusicians gestures on these components. We believe that Rouages opens up newperspectives to help instrument makers and musicians improve audienceexperience with their digital musical instruments.