Due to the miniaturization of computers, wearable computing has attracted great attention. Several text input interfaces for wearable computing devices have already been proposed. However, those devices are not customized for specific users, so the devices do not facilitate sufficiently easy and quick text input. Therefore, the goal of our study is to construct a text input method specialized to pianists by exploiting characteristics of pianists and claviers. The proposed method achieves simple and quick text input by restricting users to pianists. The results of the evaluation suggest that the input speed achieved using proposed interface is twice as fast as that of the Twiddler.