Re: Key signatures in MIDI output

[Hans Åberg]

> On 10 May 2024, at 20:18, mskala@ansuz.sooke.bc.ca wrote:
> 
> On Fri, 10 May 2024, Hans Åberg wrote:
> 
>> To change the MIDI output, you will need to change the notes, say by
>> transposing or something else.
> 
> MIDI files can include events ("key-change meta messages") for key
> signatures, each specifying a root and whether it's major or minor (which
> actually makes them more expressive than standard notation which can't
> distinguish, for instance, between C major and A minor).  Lilypond
> generates these events in the MIDI files on each key change in my
> installation.  If Giles's installation appears not to, I wonder whether
> that may be due to an issue with the software he's using to examine the
> MIDI files.
> 
> For instance, this input produces a MIDI file with key-change events at
> the indicated places:
> 
> \score {
>  \new Voice {
>    \key c \major
>    c'4 d'4 e'4 f'4 |
>    \key d \minor
>    bes4 a4 g4 f4 |
>  }
>  \layout { }
>  \midi { }
> }

Programs like ABC work so that one writes the music without accidentals, and 
then apply a key signature to get them. It was my reading that the OP asked for 
that.