the only time pure intonation might be a matter of importance is in unaccompanied vocal music in which close harmonies are desired, such as a capella choirs and barbershop quartets.

It's essential to the sound of the nyckelharpa, the hammered dulcimer, the Cajun accordion, and almost all diatonic harmonicas (which are probably the commonest musical instrument on earth). These are not subtle effects: it stands out a mile if you don't have the predominant intervals tuned pure.


the vast majority of music requires that Db be enharmonic to C#. Anything you're going to use a piano or a guitar on is going to require that

And essentially zero percent of traditional music was conceived for the piano or for melodic playing on the guitar.

Just show me *one* traditional tune from anywhere and any age that uses enharmonicity.