Abstract: A method and apparatus for limiting which player pianos can properly play notes within a media file or stream without playing additional “bad notes” encoded in the stream for disrupting the playback of that musical composition so as to prevent playback on unauthorized systems. Bad notes are encoded within a file or stream containing the proper “good notes” of the composition along with control commands to allow identifying the bad notes (e.g., by location, relative position, characteristics and so forth). Player pianos of a first manufacturer, having the proper programming, properly decode the control commands to locate the bad notes and prevent them from being played back with the good notes, therein properly rendering the musical composition. Player pianos from other manufacturers will play all the notes thus obfuscating the playback of the musical composition. Fidelity of playback on authorized system is not affected.

Abstract: A piano pedal optical sensor apparatus and method for accurately measuring, recording and reproducing the pedal expression generated during piano performances. A plurality of optical emitter/sensors are mounted on the pedal support assembly of a piano, and a plurality of corresponding optical reflectors are mounted on the moving connecting rods associated with piano pedals on the piano. Output voltage signals from the optical emitter sensors, which vary according to pedal movement, are monitored and used to generate and record pedal position values. The recorded pedal position values are then used to recreate the original pedal expression of the piano performance by generation of pulse width modulation signals which are used to drive solenoids associated with piano pedals.

Abstract: A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned adjacent to the keys. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through.

Abstract: A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned above the hammer catchers. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through.

Abstract: A method and apparatus for accurately sensing key motion in a keyboard operated musical instrument, in which optical emitters and sensors are positioned above the hammer shanks. The optical emitters and sensors are arranged on a plurality of individually addressable sensor boards, and the sensor boards are divided into a plurality of individually addressable sensor banks. Each sensor board is independently and sequentially activated by a controller according to a specified timing sequence. As the controller activates a sensor board in one bank, allowing the board to warm up, another sensor board in the second bank, which has previously been activated and warmed up, is read and analyzed by the controller. Activation and reading of sensor boards alternates between sensor banks as the sensor boards are sequenced through.