Technically, regardless of the rest of the product design there are high quality potentiometers available both as linear faders or rotary knobs. I guess dirt is more likely to get into a linear fader and make it scratchy - especially in a club environment.

But the same thing could be done as a post-processing step, finding points where the spectrum is changing fast and resetting the phases to make a sharper transient.

(Polytune is more robust than just doing this and does work really well, but if the guitar is really out of tune the method falls apart and you have to use its one-string-at-a-time mode)

https://www.firstpr.com.au/dsp/pink-noise/ http://stenzel.waldorfmusic.de/post/a-new-shade-of-pink/

This part isn't practice, it's the pupils contracting that improves the focus like looking through a pinhole does.

A better way is parabolic interpolation, which is in the source code but not mentioned in the article - and that works for finding the fractional position of peaks in the FFT or in the autocorrelation.

An even better way is by comparing the phase of the peak in two successive FFTs: If the signal phase has changed by X degrees after T seconds, what's the nearest frequency to the bin centre that can be true for? (this is the main thing a "phase vocoder" does)

If we sensed sound like we sense colour we'd only hear the amount of bass/mid/treble not the individual pitches.

But if there's such a thing as a non-linear medium for light, then transmitting two wavelengths through it should do interesting things depending on the ratio of the wavelengths?