Abstract: A device which can be used to control a musical performance contains a sensor which outputs an electrical signal. The sensor may be formed by providing a fixed contact and a hollow contact, wherein movement of the device causes the contacts to meet. Other features of the device include a user-adjustable sensitivity feature, a button for starting/stopping, and a sliding switch for sending volume information to the playback devices. The device may be provided as part of a system which includes a score-following apparatus.

Abstract: The invention is directed to a switch arrangement for signaling the movement and the inclination of the switch arrangement which is accommodated in a housing. The switch arrangement (2) includes a first switch (12) configured as an On/Off switch and a second switch (10) connected to a capacitor (K). The switches include each conductor portions (22, 24) adapted to be connected to each other by a movable actuating member (18). While the switch (12) signals both the movement and the inclination of the arrangement (2), the switch (10) signals a movement of the arrangement (2) by issuing pulse signals. In the position of the rest of the actuating member (18), none of the switches is activated. In one configuration of the switch arrangement, the actuating member is guided in a cutout whose sides extend towards each other in a converging fashion.

Abstract: A rotatable one-piece lens assembly that may be rotated relative to the instrument housing comprising a lens boss, integral with the lens, moving with the rotated lens to move the pointer to engage and test the switches. After the switch test the lens may then be rotated back to its normal position. In this manner the switches are tested without removing the lens from the instrument housing.

Abstract: A device is disclosed which, in response to forces acting upon it, such as gravity, inertia, magnetic fields and the like, opens or closes electric circuits or otherwise generates signals which may be used to control predetermined functions.