The one genre I can think of where perfect tuning is essential is barbershop music. The defining feature of the genre is chords sung with just intonation and no

The one genre I can think of where perfect tuning is essential is barbershop music. The defining feature of the genre is chords sung with just intonation and no vibrato, which makes it easy to hear if any of the singers are out of tune. See: https://en.wikipedia.org/wiki/Barbershop_music#Ringing_chords https://en.wikipedia.org/wiki/Barbershop_music#Ringing_chord...