Learning to play the guitar is difficult. We proposed a system that assists people learning to play the guitar using augmented reality. This system shows a learner how to correctly hold the strings by overlaying a virtual hand model and lines onto a real guitar. The player learning to play the guitar can easily understand the required position by overlapping their hand on a visual guide. An important issue for this system to address is the accurate registration between the visual guide and the guitar, therefore we need to track the pose and the position of the guitar. We also proposed a method to track the guitar with a visual marker and natural features of the guitar. Since we used marker information and edge information as natural features, the system could continually track the guitar. Accordingly, our system can constantly display visual guides at the required position to enable a player to learn to play the guitar in a natural manner.