Robots are usually capable of carrying out one kind of specific task automatically at the same level with human. The mechanisms on those robot are designed only to adapt with conducting certain series of actions, and therefore, the same complexity as human body is not needed. The Waseda Anthropomorphic Saxophonist robot (WAS) is developed since 2007 to accomplish performing saxophone at the level of a human professional. However, the register it can perform is still limited and needs to be improved. In the research, we analyzed the movement of a saxophonist's upper limbs and found out the significant joints he used when playing with table key, a group of keys on the saxophone used to perform lower register. As the result, a simplified model of robot limb was developed and its capability was verified by comparing with the experimental result.