building an instrument tuner

first attempt: fourier transform

waveform of some wave, sampled at 44100Hz:

transformed into the frequency domain:

the peak is at hz.

more resiliant approach: auto-correlation

yin paper

same waveform as above:

the autocorrelation, stopping at the halfway point:

the fundamental frequency estimate is hz.

final piece: pitch frequency to note name

the estimated note is .