Movable-Do note input mode for computer keyboard

Your idea

A Movable-Do note input pattern which determines the pitch according to the current key signature.
For example, when C is pressed in a staff with a D-Major or B-minor key signature, the actual pitch should be D instead of C.
A keyboard shortcut that switches between Movable-Do mode and conventional mode will be helpful.

For consistency, it would be better to use other keys rather than A~G for Movable-Do note input, for example, D R M F S L T for Do Re Mi Fa Sol La Ti. However, doing so will currently be problematic since alternative keys are likely to conflict with existing keyboard shortcuts.

Problem to be solved

Many people learn music and read standard music notation in Movable-Do (especially in China where JianPu is widely used as a beginner aid), and usually do not talk about pitches in ABC unless when trying to specify an absolute pitch. Most are capable of understanding ABCs and Fixed-Do, but are not used to thinking in this way when improvising by ear.

Having to convert the relative pitches into Fixed-Do pitches before entering can be extremely awkward, significantly slowing down the process of composing. Hence a Movable-Do input mode can make music practice and composition a lot more accessible to these people.

Prior art

No response

Additional context

There is a workaround for now. By using the transposing feature, the user can transpose the written key signature to C-Major or A-minor without affecting playback.

However, this is still inconvenient if chromatic alterations exist. Doing so will also (definitely) change the score to show C-Major instead of the proper key signature. In order to confirm the engraving or confirm that the melody is in the proper pitch range, one have to switch to Concert Pitch.

No files, tests, or entry points are named. Start by locating the computer-keyboard note-input and keyboard-shortcut handling, then review how key signatures affect entered pitches. Done should include a switchable Movable-Do mode, conflict-free shortcuts, correct pitch entry under key signatures, and coverage for the described cases.