Re: Stem direction of grace notes when main note is stemDown

[Knute Snortum]

On Sun, Jun 12, 2022 at 1:33 AM Paul Hodges <p...@cassland.org> wrote:
>
> Gould says all grace note have stems up, except (1) when there are two parts 
> on a staff, (2) in a double stemmed group, (3) when the group is on the beat, 
> sharing a note head with a main note whose stem is up.
>
> Paul
>
[Jean]
>
> What would you then do with
>
> <<
>   { g'4 g' g' \acciaccatura a'8 g'4 }
>   \\
>   { c'4 c' c' \acciaccatura d'8 c'4 }
> >>
>
> ?
>
> I don't have Gould at hand right now, but my clue is that the
> rule reads: in single-stemmed writing, grace notes are always
> up, even if their natural direction would be down, as in
>
> { c''4 c'' c'' \acciaccatura d''8 c''4 }
>
> In double-stemmed writing, however, I don't believe it's
> standard to do that.

Thanks Paul and Jean.  I've attached a fragment from Chopin's Preludes
Opus 28, no 12, to illustrate my point.  Which looks better, my way or
the Lilypond default?  Or is there another way?

--
Knute Snortum

\version "2.22.2"
\language "english"

\layout {
  indent = 0
  ragged-right = ##t
}

\relative {
  \key gs \minor
  \time 3/4
  % Divide eight notes by twos
  \set Timing.beamExceptions = #'()
  \set Timing.baseMoment = #(ly:make-moment 1/4)
  \set Timing.beatStructure = 1,1,1
  <<
    { b'2.~^"My way" | b2. | }
    \\
    {  
      <e, g>8_( <d fs> \acciaccatura { \stemUp g8 } \stemDown <d fs>8 <cs e> 
        <d fs>4) |
      <e g>8_( <d fs> \acciaccatura { \stemUp g8 } \stemDown <d fs>8 <cs e> 
        <d fs>4) |
    }
  >> \break
  <<
    { b'2.~^"LilyPond default" | b2. | }
    \\
    {  
      <e, g>8_( <d fs> \acciaccatura { g8 } <d fs>8 <cs e> <d fs>4) |
      <e g>8_( <d fs> \acciaccatura { g8 } <d fs>8 <cs e> <d fs>4) |
    }
  >> 
}