Sometimes in early music history, there were keyboards with more than twelve notes per octave. They were pretty difficult to play but gave the possibility of playing music way more in tune than our twelve equally distributed notes per octave system permits. As an example, enjoy this performance and ... count the number of notes per octave on the harpsichord!! Notice how the violin does not need to do vibrato as there is no intonation inaccuracy to hide. There is more to talk about after having heard this performance... as you will notice "strange" things happening...
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