One of the traditional musical instrument from Indonesia is <em>gamelan</em>, that is now less desirable because people nowadays prefer to play modern musical instruments, or because of its expensive price. This study combines the modern technology of AR and Leap Motion and also utilizes the sophisticated smartphone to develop a <em>gamelan</em> simulation that is presentable to the user. There are two kinds of an experiment performed in this research. The first is Augmented Reality (AR) experiment which authenticates that the distance and the height parameters are the keys to get a 100% success in running the <em>gamelan</em> simulation. The distance is ranged from 45 cm to 65 cm and the height is ranged from 25 cm to 30 cm. And the second one is the usability evaluation to five users, who resolves the completion task very well, acquires the result of 86.48%.