Emulating Digital Linear FM Synthesis with "Analog" AM ( Remove Different Orders of Harmonics )

This is basically the Melodyne Spectrum Editor for broke ass people. Got the idea when i thought about frequency shifting and realized that if you frequency shifted down a monophonic signal only containing partials in harmonic ratios like in simple common synthesizer oscillators/ string reed or brass tones you would get for example the original overtone structure again but missing for example every second harmonic because you in a way stretched the overtone spectrum of the original signal so that every original harmonic would be at a different whole number ratio in the downshifted spectrum. However with reasons proprietary frequency shifter i couldn't test or realize that idea since you can't set it to precise frequencies as far as i can tell (maybe there's a workaround ). But that got me thinking about amplitude modulation. As i said in previous video descriptions frequency shifting is just single side band amplitude modulation and amplitude modulation just creates another side band. I then thought if frequencies down shifted by frequency shifters or amplitude modulation get reflected back up in the frequency spectrum but with negative polarity ( phase ) wouldn't they cancel out if you shifted a frequency by the double of it's own amount ( as far as i can remember this is how i discovered this ) . The important thing here as i tried to show with the free running "analog" oscillator in the beginning is that modulator and carrior oscillator need not only to have a harmonic ratio but also a certain phase relationship in order for it to work optimally and completely cancel out certain orders of harmonics. It's also important to mention that this process works best with primitive simple common oscilator waveforms since unlike most other waveshapes their harmonics are also "in phase with each other" so to say. The effect will be different and weaker when a waveforms harmonics have very complex phase relationships. This can also be implemented in purely analog circuitry i think. It's often said that analog oscillators aren't pitch stable enough for this type of fm synthesis ( linear fm ). But since i've come across phase locked loop harmonizers ( PLL ) ( like the one used in the data corrupter effects pedald by earth quaker devices ) or triangle waves put through sine wave shapers both processes producing purely harmonic ratio output signals i think it can be done.