Re: lilypond errors on a guitar minor sixth chord

[Thomas Morley]

2017-04-14 5:18 GMT+02:00 Stan Mulder <address@hidden>:
>
> Thomas,
>
> Here's your example, but with fretboards added. The error is there. 
> Apparently it has to do with fretboards. Also, I am running 2.19.59:
>
> \version "2.19.56"
> \language "english"
> \include "predefined-guitar-fretboards.ly"
>
> m = \chordmode {
>   \override FretBoard.fret-diagram-details.dot-radius = #0.4
>   \override FretBoard.fret-diagram-details.number-type = #'arabic
>   b-flat4 bf/f g4:dim/e e-flat:m6
> }
> <<
> \new ChordNames \m
> \new FretBoards \m
> \new Staff { \accidentalStyle forget \m }
> >>
>
> Error:
[...]

Hi Stan,

please always reply to all, unless real private topics are discussed.

I now get the _warning_ myself.
So this is a good show-case about minimals. Obviously your
code-example should have pointed to FretBoards:

\version "2.19.59"

\language "english"
\include "predefined-guitar-fretboards.ly"

\new FretBoards \chordmode { e-flat:m6 }

Would have done it.


That said,

Some basics:

Lilypond creates FretBoards (without predefined-guitar-fretboards.ly)
by looking at the actual chord-pitches.
Which are < ef' gf' bf' c'' > in this case. Here LilyPond thinks it's
not doable and indeed it would be very hard to do something like:
\new FretBoards { < ef'\4-4 gf'\3-2 bf'\2-3 c''\1-1 > }

If predefined-guitar-fretboards.ly is included, LilyPond looks there
whether a fret-diagram-definition for the chord is stored there.
If found it's taken otherwise lily falls back to look at the actual
chord-pitches.

In predefined-guitar-fretboards.ly are definitions stored for all
chords of type:
major, minor, 7, m7, dim, aug, maj7, dim7, 9

Thus Lilypond does not find m6-chords, falls back to the pitches,
can't find a sensible fret-diagram, prints what's possible and finally
emitts the warning about the missing part(s).



Sollution(s):

(1)
Define it yourself, search the NR for 'storePredefinedDiagram'. Leading to:

\version "2.19.56"

\language "english"

\storePredefinedDiagram #default-fret-table \chordmode {e-flat:m6}
                        #guitar-tuning
                        #"x;x;1-1-(;3-3;1-1-);3-3;"

\include "predefined-guitar-fretboards.ly"

\new FretBoards \chordmode { e-flat:m6 }

(2)
Look at
http://lists.gnu.org/archive/html/lilypond-user/2017-02/msg00500.html
and follow the link to Philomenos
Although I have to admit I never tried it myself.

(3)
Extend predefined-guitar-fretboards.ly
That would mean to create a patch for the missing chords.

Though I'm not sure to which amount such a patch would be accepted.
Currently only the "most common" chords are stored there. Ofcourse
it's debattable which chords are "most common"...
And if we extend the file, what comes in what not?
11, 13, b5, inversions, added bass-pitches, etc etc
The Philomenos-files obviously try to cover most possible, so their
files are of huge size ...
I'd say too huge to ship them with default LilyPond.


HTH,
  Harm