Re: Question about output

[Benjamin Strecker]

On Wed, Apr 27, 2016 at 11:51 PM, Michiel Sikma <address@hidden> wrote:
>
> Hi all,
>
> I'm doing some tests trying to figure out repeating sections and voices, and 
> I've written this so far:
> http://lilybin.com/mwafar/2
> My question is, does it look OK to you that the end of the second alternative 
> is a repeat bar (e.g. ":..:" ) in both directions? I was expecting to get a 
> ".|:" bar. Here's an example: http://i.imgur.com/PJ9prg1.png
> Did I accidentally mess up the repeat formatting or is Lilypond's output also 
> valid? To me it looks almost like there should be another repeat of the first 
> part, after playing the second alternative, which is not how the score should 
> be, but maybe I'm mistaken.
>
> I appreciate any insight you can give, or other tips if you happen to think 
> of any :)
>
> Michiel Sikma
>

The short answer is that you didn't _quite_ handle the repeat
structure correctly.  You have the repeat and alternatives all set up
in the right hand part, but in the left hand part, you don't have the
alternatives, just the repeat, so that adds the left-facing repeat
dots at the end of the second alternative.  To me, that is a confusing
appearance, because, as you said, it looks like there's yet another
repeat back to the top.

One thing that I like to do (and I'm pretty sure others will back me
up on this) is have a global voice that contains key signature
settings, tempo indications, repeat structure, etc.  In your case, it
might look something like this for the first repeated section:

global = {
  \key c \major
  \time 9/16
  \tempo "Adagio molto semplice e cantabile"
  \repeat volta 2 {
    \partial 8. s8. |
    \repeat unfold 7 {s4. s8.}
  }
  \alternative {
    {
      \set Timing.measureLength = #(ly:make-moment 6/16)
      s4.
    }
    {
      \set Timing.measureLength = #(ly:make-moment 9/16)
      s4. s8.
    }
  }
}

Then, you just add that as another simultaneous voice.  This means you
don't have to re-create the repeat structure precisely in every single
staff, which is particularly handy when working with a large score
with many staves.

Hope this helps,
Ben