A detection device includes: a movement detector that includes light emitters and light receivers, wherein in accordance with movement of a moving body among moving bodies, each corresponding to a different combination of a light emitter and a light receiver, a light reception level of the light receiver in a combination corresponding to the moving body changes; and a processor coupled to a memory storing instructions that, when executed by the processor, configure the processor to: cause each of the light emitters to sequentially emit light in each light emission period by providing a driving signal, and cause a signal level of the driving signal to differ between unit periods within the light emission period; and select, for each light emission period, a light reception level in one of the unit periods within the light emission period as a detected value for each of the light receivers.

This disclosure concerns an input keyboard which works in unison with a compatible operating program to produce piano chords. The keyboard incorporates strategically placed pairs of actuator switches that are tied together in unison by a lengthways-positioned rectangular bar that is attached on top of each one of the actuator switches by a flexible fastener means with each actuator switch being attached directly underneath each end of the rectangular bar. This conglomeration is referred to as a Piano Chord Producing Bar. Each piano chord producing bar is programmed to produce full or partial piano chords when depressed. Piano chord producing bars are plurally arranged in horizontal parallel rows that extend from the left to the right side of the keyboard. Piano Chord Producing Bars keyboards with their compatible operating programs can be incorporated into electronic keyboard musical instruments or used as controller keyboards for input into various devices.

An electronic music generating device may include key assemblies. Each key assembly may include a base, an arm having a proximal end pivotably coupled to the base, and a cap carried by a distal end of the arm. Each key assembly may include a foot coupled to a distal end of the arm and extending down to the base in spaced relation from the proximal end of the arm, and a stop member carried by the base and to engage the foot upon movement of the arm to a depressed position. Each key assembly may also include a biasing member coupled to the arm and to engage the base for biasing the arm to an unpressed position, and a magnetic position sensor associated with the foot. A controller may cooperate with each magnetic position sensor to generate a sound based upon a sensed position of each foot.