"First, some history. Fretted instruments have traditionally been tuned to "equal temperament," a system based on a formula going all the way back to Pythagoras. Problem is, some keys are created more "equal" than others. ”
Here, Buzz’s grasp of history seems as shaky as his understanding of music.
He attributes the development of Equal Temperament to Pythagoras, but there is nothing “equal” about the Pythagorean scale; Pythagoras devised the “Pythagorean comma” - a tiny interval which could be added to other intervals in the scale - to resolve the discrepancies in his scale which had several unequal intervals and a “greater” and “lesser” semitone.
The various pre-equal temperament systems had no analog in the world of fretted instruments which is why the lute was at the forefront of developing systems of tuning which sought to close the gap between the aesthetics of music and the practicalities of musical instrument construction.
Fretted instruments have used a system of “Constant Ratio” proportional fretting since the 1600s but this was not Equal Temperament as we know it today and was not universally adopted until the later Baroque era and the development of fixed fretting techniques. Many early instruments used frets formed of loops of gut tied around the fingerboard and pushed into place to tune by ear and many lutenists and viol players developed their own favoured rules for fret positioning, many of which were nowhere near Galilei’s constant ratio “rule of 18”
The Orwellian reference to some keys being created more “equal” than others is meaningless.
