Add a "scale select" drop down for Note in Key exercise.

[ShacharHarshuv]

This should not be mapped to any specific settings field, but set the "cadence" and "included options" properly.

For example, if you select "Minor" scale then the cadence should be the minor cadence (i iv V i), and the included answers should change accordingly. If "Mi was selected then "Me" should be selected instead etc.

[entomologe]

Would it be useful to add more scales apart from major and minor (e.g. modes of (pentatonic, minor, etc.) scales)?

[ShacharHarshuv]

Yes, once we get the basic infra of this, I imagine it would be easier to add as many scales as we want.