Music learning (here, thinking of playing piano) without professor can be a real challenge. This can be difficult to achieve, given some traditional approaches to manage this process are still insufficiently satisfactory. Beyond the wellknown computer-assisted music learning tools (1) screenbased and (2) hardware-based, a promising solution for piano learning is based on augmented reality (AR). This technology provides an ideal environment for the student, but of course, it is not enough to become a career musician. In this paper, we propose an application that helps all those who want to learn to play the piano in a friendly way, starting with understanding sheet music. By projecting information onto the instrument, our AR system can create more direct interactions for the user.