Re: alternative volta 2 when empty

[mskala]

On Sun, 29 Sep 2024, Walt North wrote:

> What would be the correct way to code the following case?
>
> I have a repeated section.  The first alternative volta has a couple of
> measure before going back to the repeat.  The second volta should just carry
> on with the remainder of the piece.  I'd like to have an indication of the 2.
> volta just to show where to carry on forward., The coding I have only shows
> volta 1. but not the (empty) volta 2.  I don't want the entire remainder of
> the piece to be under volta 2.  I rather not split out just the first measure
> of the remainder of the piece just to put it under volta 2.

Two separate issues here:

1.  What is the best (easiest to read, most standard) visual notation to
expess this kind of repeat?

2.  How should you code this in Lilypond to get the notation you think
best?

I think that if you must use a volta-bracket repeat, then splitting out
the first measure of the remainder of the piece to put that under the
volta 2 bracket really is the most standard way to answer question 1.
There's no nice way to draw a zero-width volta bracket.  So if you want
the visual appearance of a bracket over the first measure of the
remainder, and your concern is only with question 2 - how to conveniently
print it - then you might get some benefit from putting the repeats in a
separate variable and merging:

ch = \chordmode {
  c1 c
    d d d d
    e e
  f f f f
}

rp = {
  s1*2
  \repeat volta 2 {
    s1*4
    \alternative {
      \volta 1 { s1*2 }
      \volta 2 { s1 }
    }
  }
  s1*3
}

\score { \new ChordNames { << \ch \rp >> } }

However, you might want to consider different answers to question 1.  In
particular, this kind of structure would be easy to create with a segno
repeat.  And if you want to stick with a volta repeat, you could also do
it by duplicating the last measure of the unchanging repeated part, making
both alternatives a measure longer:

ch = \chordmode {
  c1 c
  \repeat volta 2 {
    d d d
    \alternative {
      \volta 1 { d e e }
      \volta 2 { d }
    }
  }
  f f f f
}

Then you get both volta brackets nonzero-length, without needing to put
any of the "f" music under a bracket.

I think duplicating the last measure of the "d" music may be the best
answer depending on the circumstances.  If the "f" music represents a
structural division, then putting part of the "d" music under the volta
bracket may better represent the logical structure, and be more consistent
with the "when it doubt, write it out" principle for repeats articulated
by authorities like Gould.  In general, if you're going to use repeat
notation in a part that a performer will play, then it's really important
that the repeats should not confuse the performer.  Writing out the music
a second time is almost always less confusing, although that must be
balanced against considerations like avoiding inconvenient page turns.

-- 
Matthew Skala
mskala@ansuz.sooke.bc.ca                 People before tribes.
https://ansuz.sooke.bc.ca/