Electronic tuner. Idem with microphone to better capture the sound.
In music, a tuner is an electronic device that indicates through a visual signal (galvanometer, LCD or light diodes) the difference in cents between the interpreted sound and the absolute that is the note La 440. Some models may also generate the desired frequencies, to serve as a when tuning.
The concertmaster, who gives the la3 to tune the orchestra, previously uses a tuner to adjust his instrument. There are also chromatic type tuners, which are used to tune by natural, sharp or flat notes.
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