A laser light-based control system that makes use of intelligent motion tracking camera-based technologies to allow a performed to select notes, to provide a range of values for controlling device components (such as a fader), and to select a volume or magnitude value for a selected note (or output value). The control system may be configured in some implementations with the ability to filter out other light sources to only monitor a particular light from a source using real time video processing. This allows the control system to function to track simple and also complex laser animations and beam interruptions and, in response to the results of such tracking, to generate control signals for a digital music instrument to generate an endless amount of note values and variables (e.g., volume, pitch, and so on) in a 2D space or, in some preferred embodiments, a three dimensional (3D) space.

A wearable sensor system is disclosed that provides a measurable magnetic field that changes horizontally within the range of motion of human limbs. The wearable sensor system includes a magnetic sensing device, and one or more magnet devices that provide the measurable magnetic field with a strength exceeding the Earth's magnetic field. To this end, the magnetic sensing system provides a personal magnetic field about a user, with that magnetic field traveling with the user and overpowering adjacent interfering fields. The wearable sensor system may include a sensor arrangement that measures a strength of the personal magnetic field and field direction to perform horizontal localization, and may send a representation of a same to a remote computing device to cause an action to occur. Some such actions include output of pre-recorded or synthesized musical notes, for example.

An instrument playing apparatus has: a movable member configured to be displaced responsive to a playing operation of a user; a detection part formed from a magnetic or conductive body and disposed on the movable member; and a filter that includes a coil. The filter has a frequency response that changes depending on a distance between the detection part and the coil, and generates a detection signal from a reference signal.