A musical instrument having a displacement member that is operable to vary sounds, thereby offering a wide variety of musical performances. A box-shaped sound generation unit accommodated in the inside of a musical instrument body generates a sound in response to any one of performance operators being operated. At least part of a displacement member provided for displacement relative to the musical instrument body is always disposed within the inside of the musical instrument body. When an operating section is operated to cause the displacement member to be displaced as a sound is generated from the sound generation unit, the sound varies according to the displacement of the displacement member.