Re: Figured bass, Was: Re[2]: using 'flat' or # in a title

[Mats Bengtsson]

> >>>>> "Mats" == Mats Bengtsson <address@hidden> writes:
> 
>     Mats> It would be easy to add a new chord style that outputs figures,
>     Mats> but I definitely doubt that anyone would be happy about it.
> 
> I can imagine an implementation of a chord style that would realize a
> figured bass in the MIDI output, but I certainly don't know enough to
> write it.  

Agreed that this would be nice.

>     Mats> The reason is that the chord implementation internally represents
>     Mats> each chord as a list of notes, which than is translated into the
>     Mats> corresponding chord symbol. We have had long discussions on the 
>     Mats> lists on all the different standards for chord notation and I think
>     Mats> the figured bass notation in baroque music is even less 
> standardized.
> 
> I'm not sure about that.  That is, of course what a good continuo
> player does to realize the part isn't standardized at all, but what 6
> means when put over an A in a given key signature is pretty standard.

What I had in mind was all these implicit rules that a 4 often implies
a 4,5, that a 3,4 often implies a 3,4,6 and so on. Such rules should
not be implemented in Lilypond since there's no standard way to 
invert the process. Even the same composer may sometimes write out
all the numbers, and sometimes skip the obvious ones. Of course, 
the MIDI output could include some of this intelligence.

>     Mats> Also, I'm certain that almost all of us who use Lilypond to typeset
>     Mats> baroque music are trying to produce Urtext editions and especially
>     Mats> for figured bass we should be able to typeset exactly what the 
>     Mats> composer wrote himself in the manuscript. 
> 
> I agree that we should be able to do this; I'm not at all sure that
> urtext is what we're all trying for.  I'm most often trying for
> something I can transpose to play with my 415 recorder, or into a good
> key for my serpent.

I don't think you change the figured bass when you transpose, do you?

>     Mats> Today, I know that some people, including Laura, typeset figured 
> bass
>     Mats> using a Lyrics line. This has the advantage that you get 
> horizontally
>     Mats> aligned figures for each staff line. I'm not sure how convenient it
>     Mats> is when you want to stack several figures on top of each
>     Mats> other. 
> 
> No lyrics are at all convenient in lilypond, which puts them
> in a completely different place from the notes.  In ABC, where I still
> do most of my data entry, it's a lot more convenient; if there are
> figures on most of the notes, typing them is pretty easy.  You're
> right, the ones on top of each other are less convenient, especially
> since abc2ly doesn't understand resynchronizing the lyrics with the
> notes at a line break.
> 
> The major problem I have with the stuff I've done is that when you
> have two figures on the same note, the spacing doesn't come out right.
> 
> If you look at
> http://serpent.laymusic.org/lconrad/homepage/music/schutz/jubilate/fagotto.ps,
> or
> http://serpent.laymusic.org/lconrad/homepage/music/schutz/jubilate/fagotto.ly,
> you can see that the first note in the fourth measure of the bass
> line, the 6 should be directly under the note, and the 5 should be
> half way between the note and the next note, and they're both in the
> wrong place.

Yes, the default is to align each syllable centered to the note head.
The following trick will give the desired left aligned syllables
\paper{
  ...
  \translator{
    \LyricsVoiceContext
    LyricText \override #'self-alignment-X = #'-1
  }
  \translator{
     \ScoreContext
    \remove "Lyric_phrasing_engraver"
  }
}
I had to struggle a bit to find the solution, there are some 
missing links in the autogenerated documentation.

>     Mats> I myself, typeset figured bass using text scripts. This will not 
> give
>     Mats> the horizontal alignment but keep the figures close to the notes.
>     Mats> Also, it's easy to stack them vertically.
> 
> I don't do that largely because it seems like a lot more typing.

I don't the number of key strokes differs that much. Maybe when you
go via abc2ly.

>     Mats> To summarize, I would definitely be willing to try to implement
>     Mats> a better support for figured bass, but honestly I cannot see 
>     Mats> how to design any such system that's better than what you can
>     Mats> do today (except for the symbols). If you have any good ideas, 
>     Mats> please post them here. 
> 
> As I said, some way to get the horizontal spacing better is what I
> chiefly need.  Maybe a special lyrics mode?  That would allow some
> syntax for vertical symbols?

I hope I have shown a workaround for the horizontal positioning. 
I wonder how difficult it would be to support "chords" in lyrics, 
so you could write for example:
"6" <"3" "4"> 

Another issue; nowadays most people typeset the figures below the
staff whereas most manuscripts and original editions have them
above the staff. So far, I've kept to the old practice, at least
as long as I don't provide any realization of the figures bass.
This will affect if you want to align the top or the bottom figures.

   /Mats