A method and apparatus for self-tuning a piano that optically senses the vibration of all the piano's strings independently and simultaneously. Interference caused by alternating-current ambient lighting is removed by modulating the string's signal onto a high-frequency carrier wave, filtering out the low-frequency ambient light interference wave, then demodulating and removing the carrier to render the original signal. Digital pitch, diagnostic, and control parameter information is interchanged between a supervisory master microcontroller and the autonomous string sustainer circuits via a master-slave serial bus connected through a single, common cable. PWM duty cycles for the string tuning coils are handled autonomously by an FPGA or a decoder network, which also communicates with the master control circuit. Pulse-width modulated control signals are filtered to a DC control voltage and combined with a drive oscillator signal using a summing amplifier to eliminate audible noise due to magnetostriction in the tuning coils.

A method and apparatus for self-tuning a piano that optically senses the vibration of all the piano's strings independently and simultaneously. Interference caused by alternating-current ambient lighting is removed by modulating the string's signal onto a high-frequency carrier wave, filtering out the low-frequency ambient light interference wave, then demodulating and removing the carrier to render the original signal. Digital pitch, diagnostic, and control parameter information is interchanged between a supervisory master microcontroller and the autonomous string sustainer circuits via a master-slave serial bus connected through a single, common cable. PWM duty cycles for the string tuning coils are handled autonomously by an FPGA or a decoder network, which also communicates with the master control circuit. Pulse-width modulated control signals are filtered to a DC control voltage and combined with a drive oscillator signal using a summing amplifier to eliminate audible noise due to magnetostriction in the tuning coils.

An information processing device (2) includes an acquisition unit (22) that acquires detection results of a plurality of sensors (1) that detects skill acquisition operation, and a processing unit (24) that processes the detection results of the plurality of sensors (1) which results are acquired by the acquisition unit (22). The plurality of sensors (1) includes a main sensor (11) that detects a state of a main operation target in the skill acquisition operation, and the processing by the processing unit (24) includes extracting a plurality of pieces of information in the skill acquisition operation on the basis of a detection result of the main sensor (11), calculating feature amounts acquired from the detection results of the plurality of sensors (1) in a generation period of each of the plurality of pieces of extracted information, and generating data (23b) in which the detection results of the plurality of sensors and the calculated feature amounts are organized and described for each of the plurality of pieces of extracted information.

In one embodiment, a method for the enhanced display of the hands of a pianist playing a piano, including: (a) recording at least one video stream of at least one hand of a pianist playing a piano; and (b) while the pianist is playing the piano, using at least a portion of the piano as a display for displaying the video stream.

In one embodiment, a method for the enhanced display of the hands of a pianist playing a piano, including: (a) recording at least one video stream of at least one hand of a pianist playing a piano; and (b) while the pianist is playing the piano, using at least a portion of the piano as a display for displaying the video stream.

A music rack unit-mounting structure of a grand piano, for removably mounting a music rack unit on a piano body of the grand piano. Rear ends of a left-side engagement portion and a right-side engagement portion are configured to be capable of being placed on front ends of a left-side guide portion and a right-side guide portion from above, respectively, when the music rack unit is mounted on the piano body from the front. By sliding the music rack unit rearward from the placed state, the music rack unit is mounted on the piano body, while the left-side engagement portion and the right-side engagement portion are fitted on or in the left-side guide portion and the right-side guide portion, respectively.

A music rack unit-mounting structure of a grand piano, for removably mounting a music rack unit on a piano body of the grand piano. Rear ends of a left-side engagement portion and a right-side engagement portion are configured to be capable of being placed on front ends of a left-side guide portion and a right-side guide portion from above, respectively, when the music rack unit is mounted on the piano body from the front. By sliding the music rack unit rearward from the placed state, the music rack unit is mounted on the piano body, while the left-side engagement portion and the right-side engagement portion are fitted on or in the left-side guide portion and the right-side guide portion, respectively.