There are also guitars which take a tempered approach to tuning, and typically require a multi-scale fitment of bridge and nut. The Buzz Feiten system [1] is t

There are also guitars which take a tempered approach to tuning, and typically require a multi-scale fitment of bridge and nut. The Buzz Feiten system [1] is the first I can recall, although now many guitar manufacturers are building guitars with each string using a different scale and fanned fretboards [2]. [1] https://en.m.wikipedia.org/wiki/Buzz_Feiten#Buzz_Feiten_tuning_system https://en.m.wikipedia.org/wiki/Buzz_Feiten#Buzz_Feiten_tuni... [2] https://images.guitarguitar.co.uk/large/130/170316308819006f.jpg https://images.guitarguitar.co.uk/large/130/170316308819006f...