Re: Wrong barlines in second alternative after "repeat volta" when repeat starts with upstep

[Mats Bengtsson]

You are completely right. The implementation of the repeat handling 
should be
corrected to correspond to normal typesetting conventions. This problem 
has been
brought up on the mailing lists several times over the years, but nobody 
has fixed it yet.
Clearly, the "explanation" provided in the current manual, is completely 
wrong
according to music typesetting conventions.

A fix to this problem is to manually tell LilyPond that the second ending
should start at a bar line:

\version "2.10.0"

\new Staff \relative {
 \partial 4
 \repeat volta 4 { e | c2 d2 | e2 f2 | }
 \alternative {
   { g4 g g }
   { \partial 4*0 % The second ending starts on the first beat
     a a a a }
 }
 a b2.
}

An alternative is to manually tell LilyPond that the first ending is an
incomplete bar:

\version "2.10.0"

\new Staff \relative {
 \partial 4
 \repeat volta 4 { e | c2 d2 | e2 f2 | }
 \alternative {
   { \partial 4*3 g4 g g }
   { a a a a }
 }
 a b2.
}

   /Mats

Walter Gull wrote:
> I refer to the third example in section "6.7.2 Repeat syntax" in the current
> LilyPond documentation:
> http://lilypond.org/doc/v2.11/Documentation/user/lilypond/Repeat-syntax
>
> This example starts with an upstep. In the fourth repetition the three "g"
> quarter notes are not to be played. The note PLAYED immediately before the first
> note ("a") under the "quarta volta" hood is the half note "f", which is played
> during beats 3 and 4. Thus that first "a" has to be played on beat 1, and the
> bar under the "quarta volta" hood is an ordinary full 4/4 bar, NOT an isolated
> upstep. As a consequence the next barline should only appear between the
> second-last and the last "a" note.
>
> I modified your example using "unfold" instead of "volta" (a modification that
> should only change the typesetting, but not the playing of the music) and get a
> correct rendering.
>
> See http://gull.homeunix.org/Documentation/ly-bug-repeat/
>
> r1      literally your example snippet
> r2      modification with "unfold"
>
> r1.pdf is wrong
> r2.pdf is correct (although maybe musically not too sensible ...)
> P.S.: Sorry for typesetting the examples an an octave lower, but that is here
> irrelevant.
>
> Besides: Thank you for the great software you wrote!
>
>
>
> _______________________________________________
> bug-lilypond mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/bug-lilypond
>   

--
=============================================
        Mats Bengtsson
        Signal Processing
        Signals, Sensors and Systems
        Royal Institute of Technology
        SE-100 44  STOCKHOLM
        Sweden
        Phone: (+46) 8 790 8463                         
       Fax:   (+46) 8 790 7260
        Email: address@hidden
        WWW: http://www.s3.kth.se/~mabe
=============================================