If maintaining a one-to-one relationship of %helmholtz_to_midi keys to %midi_to_helmholtz keys is an important requirement, then, yes, you have to do something kludgy like use a compound identifier. For example:

    $helmholtz_to_midi{'a♯¹/b♭¹'}{midi_note_number} = 70;

and

    $midi_to_helmholtz{'70'}{helmholtz_note_name} = 'a♯¹/b♭¹';

But the inescapable musical fact remains:  there isn't a one-to-one relationship of MIDI note numbers to Helmholtz note names. There's a one-to-many relationship, just as there's a one-to-many relationship of pitches (440 Hz) to enharmonic notes (g𝄪¹, a¹, b𝄫¹).

In reply to Re^5: utf8 hash keys revisited: How can i use musical symbols as hash keys? by Jim
in thread utf8 hash keys revisited: How can i use musical symbols as hash keys? by karlgoethebier

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