Each acoustic instrument is one of a kind. Its unique acoustic properties are transferred from the physical characteristics of its source materials and a handcrafted touch. In contrast, electronic and computer-based instruments lack this distinguishing trait. Though the technology support in musical instruments offers great flexibility, it tends to foster predictable and generic results, particularly with common use of easily-cloned digital presets. This paper presents a new approach to the design and fabrication of instruments that combine the advantage of acoustic and electric instruments-hybrid instruments-that exist simultaneously in both physical and digital environments. This approach exploits physical/ acoustic properties via a replaceable physical object complemented by a simulated shape or other digital signal manipulation. The key concepts of this approach are presented through an example: The Chameleon Guitar, detailed in this paper along with evaluation from musicians and instrument makers. This work aims to demonstrate the possibility of maintaining the qualities found in real acoustic instruments, such as unique spectral and spatial behaviour of wooden soundboards, with the flexibility of digital processing.