Re: transposable figured bass?

[Chris Yate]

On 29 June 2015 at 14:20, Stefan Thomas <address@hidden> wrote:

Dear community,

I run in a problem, when I transpose the below quoted figured bass from g to f.

In this  special case the natural sign before the "5" in the 2nd chord should be a flat sign. Is it possible to get a transposable version of this figured bass?

Here is my example:

\version "2.18.2"
global= { \key g \major \time 4/4 }
Music = \relative g { \clef "bass" \global  g1 b, c d  g, \bar"|."  }
fgbass = \figuremode { s1
<6 5!> % here's the problem, it must be a flat sign in f major
s
<6 4>2 <5 3>
}


\markup{A figured bass in g major:}
\score {
  <<
    \new Staff \Music
    \new FiguredBass {\global \fgbass }
  >>
}

Music = \transpose g f \Music
\markup{The same thing in f major:}
\score {
  <<
    \new Staff \Music
    \new FiguredBass{ \transpose g f { \global \fgbass } }
  >>
}

This is an interesting problem and I suspect it would need some coding (Scheme?). As you probably know, docuentation says:

"Although the support for figured bass may superficially resemble chord support, it is much simpler. \figuremode mode simply stores the figures and the FiguredBass context prints them as entered. There is no conversion to pitches."

I wonder whether you or someone could write a new engraver for chords "FiguredChordsEngraver" so you would enter them as per http://lilypond.org/doc/v2.18/Documentation/notation/guitar
and see figured bass output...

Chris