Re: Automatically splitting long notes according to the beat?

[Aaron Hill]

On 2019-04-04 5:24 pm, David Bellows wrote:
> Lilypond groups beams automatically according to the beat. If you use
> the "Completion_heads_engraver" you can get Lilypond to automatically
> split long notes at bar lines tying them together.
>
> So I'm wondering if Lilypond can automatically split long notes
> according to the beat and if I am just missing something?
>
> If you have something like:
>
> {c'8 c'2 c'4 c'8}
>
> then you might want it to automatically split at the middle of the bar:
>
> {c'8 c'4.~c'8 c'4 c'8}
>
> or even on every beat:
>
> {c'8 c'8~c'4~c'8 c'8~c'8 c'8}
>
> And if it's  compound meter then it seems less optional:
>
> {\time 6/8 c'8 c'2 c'8} should be:
> {\time 6/8 c'8 c'4~c'4 c'8}
>
> Elaine Gould says on the first example:
> "When the rhythms are not part of a regular pattern, the long duration 
> may
> be divided to expose the beats or half—bar, to make the rhythm easier 
> to count
> and therefore to place."
>
> and
> "Compound Time: No note-value should be written across the beat, ..."
>
> I've been searching for a while but I haven't been able to find
> mention of this anywhere though I might not be using the correct
> search terms.

This is of course a total hack, but basically you could pretend that the 
measures are 2/4 rather than 4/4.  Then by hiding every other bar line, 
it *looks* like it is 4/4:

%%%%
\version "2.19.82"
\new Staff
  <<
    { \tweak stencil
        #(lambda (grob) (grob-interpret-markup grob #{
            \markup \override #'(baseline-skip . 0)
                    \column { \number 4 \number 4 } #}))
      \time 2/4
      \repeat unfold 3 { s2 \bar "" \noBreak s2 \bar "|" } }

    \new Voice \with { \remove "Note_heads_engraver"
                       \consists "Completion_heads_engraver" }
    \fixed c' { c8 c2 c4 c4 c1 c4 c2 c8 | }
  >>
%%%%

But there are almost certainly problems with such a kludge.


-- Aaron Hill