Re: Polyphonic repeats with lyrics (and rests)

[David Wright]

Quoting Simon Albrecht (address@hidden):
> On 19.09.2015 06:18, David Wright wrote:
> >I noticed some erroneous alto lyrics invading recent CPDL editions of
> >Farmer's Fair Phyllis. I think the cause was some overenthusiastic
> >factoring of the lyrics using tagging. So I thought I'd run up a copy
> >myself, producing folded/unfolded scores from one source file.
> >
> >However I found, like others, that repeat barlines and voltas popped up
> >all over the place as soon as I entered the lyrics into the correct
> >structure. The Notation reference manual is not much help because none
> >of its examples involves either rests or more than one vocal line.
> >
> >While none of the workarounds I've found on the web does the job
> >satisfactorily, I think it's unduly pessimistic to say, "Unfortunately
> >there is no clear recipe for entering lyrics and repeats which will
> >work in all circumstances, as all the suggestions are work-arounds due
> >to there being no well-defined interface in LilyPond for handling
> >repeats in lyrics."
> >http://lists.gnu.org/archive/html/lilypond-user/2015-03/msg00866.html
> 
> It isn’t unduly pessimistic, but realistic. The ‘right’ example you
> gave is pretty good except that it doesn’t work with \lyricsto.

Nor \addlyrics. It seems to me (not looking at the code) that, in
their search for notes to attach syllables to, both these commands
could keep a tally of rests they've skipped over in order to then
"push" the repeat mark back to the place where it belongs (which the
\relative { ... } section knows all about). That's all *I'm* after.

> However it still does not offer a good way to have different texts
> for the different repeats – I think that’s what Trevor meant by
> speaking of a ‘well-defined interface’.

I think that's further than anyone in the thread was suggesting,
though you might have read that into it. After all, it's a common
construction, I imagine. But if the words are different, then it's not
strictly a repeat, so fold/unfold doesn't apply as things stand.

You can set different words to a repeated section in the same manner
as setting multiple stanzas (like a hymn) with null voices etc if
required, but you can't then unfold it. I guess that's what you might
want to do.

> Such an interface would need
> to
> – be straightforward in entering
> – work with \lyricsto
> – allow using the same text for all repeats (using \repeat volta {}
> \alternative {{}{}})
> or different text, with simple consecutive lyrics entry and
> automated fitting into the repeat structure (at least that’s how I
> figure it), or with a \repeat lyrics {} command, or something else.
> – print braces {} around text lines for different repeats, and
> vertically center-align neighbouring lyrics without repeat (within
> one stanza this is commonly found in hymns in the Bar form; for
> complex multiple-stanza layouts see e.g. Distler,
> Mörike-Chorliederbuch on IMSLP). Perhaps \repeat stanza {} might be
> introduced. Automatic printing of stanza numbers?
> 
> So this is a really large topic, and until we have someone able and
> willing to design and implement such a feature, we are bound to
> workarounds.

I agree, but I would say that that is a different animal, and I would
hate the difficulty of doing all that design to stand in the way of
the much simpler problem (I think) of making \lyricsto and \addlyrics
do what \new Lyrics \lyricmode does perfectly correctly for lyrics
which are, like the music, strictly repeated.

The bigger problem would also, if I understand it fully, have to apply
to the music as well as the lyrics. I don't have an example to hand,
but you can imagine a piece where the "repeated" section is, say,
forte and then piano. Unfolding this is easy for the (now different)
lyrics where you've added the dynamics as if stanza numbers, but now
you've got to tell the accompanying parts by unfolding "f, repeat p"
into "f" and "p". Treating dashed slurs, anybody?

> As I said, you gave a good example there and it may well make sense
> to include it as a ‘docs’ LSR snippet. You might have a look at the
> Contributor’s Guide (via <http://lilypond.org/development.html>) for
> that.

Thanks; I'll take a look at that (and I'll stop hyphenating Now -- I).

Cheers,
David.