Abstract
There are many musical performers who want to demonstrate their performance anytime and anywhere by carrying with their musical instruments. Such kind of opportunities encourages the self-expression and the communication by music. Therefore, if they can perform anywhere, communication by music will be encouraged. However, many instruments are too big and too heavy to carry. On the other hand, portable instruments, which are suitable for carrying, have several limitations, such as a narrow range of diapason. In the case where we use such a portable clavier for playing music that has a wide diapason, playing notes frequently protrude from the diapason of the clavier. In the conventional portable claviers, it is common to use the key-transpose function, which shifts a diapason. However, this function has several problems such as uncomfortable feeling between the keying position and its output sound.
Therefore, the goal of our study is to construct Mobile Clavier, which can change the diapason smoothly and make good use of the technic acquired in a conventional clavier. Mobile Clavier can adopt problems of the key-transpose by inserting black keys between any two side-by-side white keys. Using our system, it becomes easy to play music that has a wide diapason.

Publication
Takegawa, Y., Terada, T., Tsukamoto, M., and Nishio, S. “Mobile Clavier: New Music Keyboard for Flexible Key Transpose,” Proceeding of International Conference on New Interfaces for Musical Expression (NIME2007), pp. 82–87 (June 2007).