Table of Contents
Library
In Dorico Pro, the library is the total compilation of visual items and options that are available in all projects on your computer. It combines factory default settings, custom items/options you have saved as default, and items/options only available in the current project.
Custom tonality systems
Custom tonality systems allow you to specify a unique number of divisions of the octave for your project. This can be useful for music not based on traditional Western harmony. In Dorico Pro, you can design your own custom accidentals and combine them into custom key signatures within each custom tonality.
Custom divisions of the octave
You can change the number of divisions of the octave for an existing tonality system, or create a new tonality system with as many divisions of the octave as you like.

Custom divisions of the octave

You can change the number of divisions of the octave for an existing tonality system, or create a new tonality system with as many divisions of the octave as you like.

In the Divisions section of the Edit Tonality System dialog, you can change the number of divisions assigned to each interval. The total number of divisions of an octave, which is shown at the top of the section, is updated automatically as you change the number of divisions.

In Equal temperament, or 12-EDO, the total number of divisions is 12. There are 2 divisions between A and B, 1 division between B and C, and so on. This follows the standard Western pattern which you can also see in the pattern of white and black keys on a keyboard.

Although you can divide the octave into any number of divisions, the number of equal divisions in the octave must be divisible by 12 to be able to show a standard Western key signature in Dorico Pro.