Users interact with the work by moving their bodies: movements of arms and hands (also minimal ones) are taken by a video-camera and transformed by a computer into sounds and images projected onto a screen. Each movement taking place within the field of vision of the camera is represented on the screen as a rectangle having dimensions proportional to the wideness of the movement: wide movements (i.e. of the whole body) generate wide rectangles, limited movements (i.e. of hands) produce little rectangles. The application software manages color and blend of rectangles in such a way as to obtain the best visual result. Each combination of colors (chromatic chord) is corresponding to a combination of musical notes played by a grand piano (musical chord): the wideness of the rectangle generated by the user of the work determines the note of the chord played: the wider is the rectangle, the lower is the selected note among the notes of the chord. The work was more conceived as an image generation tool than as a musical instrument, however the user may let his/her movements be driven either by aesthetic sense or ear for music. If the user, after a certain period of activity, remains still for some seconds, the application software considers the visual result as satisfactory for the user and records the image displayed onto the screen. The images generated by different users are stored in the computer memory and can be viewed afterwards.