RE: lilypond 2.7.8 bagpipe music gracenote spacing

[Sven Axelsson]

Graydon wrote:
> There's a fair bit of Highland Bagpipe music where a grace note occurs
> between two substantial notes which are not connected by a beam.
> 
> For instance:
> 
>     \grg b8[ \thrwd d8] \dble e4 \gra e8[ f8] |
> 
> (This is the second bar of "The Green Hills of Tyrol".)  The low a
> gracenote comes out much closer to the second e then the first e; it
> would be much better if it were right between the two notes.
> 
> This happens quite a bit, with various notes - A4 \grg A4 shows up
> elsewhere in that same tune. 
> 
> What I'm having trouble figuring out is how to haul the grace note to
> the left; inserting more space isn't desirable, there's
> plenty of space,
> I just want to more-or-less center the grace note in it.  (It's better
> but not ideal inside beams, such as
> 
> b8[ \grG a8]
> 
> The grace note comes out closer to the second note than the first, but
> not as close to the second note as in the 'no beam' case.
> 
> Any suggestions for how to center up these grace notes generally?

While I don't really like having the grace notes centered between the
melody notes, I do agreee that the default spacing for single grace
notes is a bit too tight.

There are a couple of ways to get round that. You can change the spacing
of all single grace notes by redefining them as:

extraSpace = \once \override Score.SeparationItem #'padding = #1.5

% Single grace notes
grG = { \grace { \small \extraSpace G32 } }
gra = { \grace { \small \extraSpace a32 } }
grb = { \grace { \small \extraSpace b32 } }
grc = { \grace { \small \extraSpace c32 } }
grd = { \grace { \small \extraSpace d32 } }
gre = { \grace { \small \extraSpace e32 } }
grf = { \grace { \small \extraSpace f32 } }
grg = { \grace { \small \extraSpace g32 } }
grA = { \grace { \small \extraSpace A32 } }

and you can fiddle with the padding to get a placement that suits you.
This doesn't look so good at the start of a bar though. To get around 
that, you could use the above definition, but rename the grace notes, 
e.g. grG -> grGpad and use the padded version only where appropriate.

Note that gracenotes are synchronized between staffs, so if you have a
score with several staffs and one staff has a doubling where the other
has a single grace note, then the doubling will not look good.

Another possibility would be to fiddle with the extra-offset grob property.
This offset is applied after the score layout has been calculated, so it
doesn't affect other items. I haven't figured out how to reference the note
as a unit, though. This changes the position of the note head only:

extraSpace = \once \override Staff.NoteHead #'extra-offset = #'(-1 . 0)

Good luck. Nice to see that someone is using the bagpipe additions.

-- 
P/S Sven Axelsson, The Murray Pipes & Drums of Gothenburg