Re: error in predefined chord diagram?

[David Kastrup]

Tim McNamara <address@hidden> writes:

> I think it depends on the purpose of the chart.  If aimed at hobbyist
> and/or performing musicians, they are likely to use their favorite
> fingerings and not necessarily what's written on the chord diagrams.
> If it is teaching materials for students, which if IIRC was the stated
> purpose of the OP, then it seems to me that it would be desirable for
> the fingerings to exactly match the notes on the staff.

Chord diagrams don't reflect keyboard chords, but a reasonable execution
of the involved notes on the guitar, closed under transposition,
correctly reflecting the inversion only in its lowest note, and not
reflecting the octave or note multiplicity at all.

Keyboard chords (the normal Lilypond chords) are for execution by
keyboard.  If you instead want the notes to reflect the chord diagram,
you'll need the same mapping function applied to the chord diagrams
applied to the chords.

It would be nonsensical to imagine keyboard and guitar chords could
match by anything but accident.

Similar considerations hold for things like accordion chords: if you
want to print _them_ rather than the specified keyboard chords, you need
an additional translation stage catering to their separate realities.

One frequently sees keyboard music with chord names and chord diagrams
above: it makes perfect sense that the notes don't match the chord
diagrams there.

On the other side, one often sees tablature/chordname/note combinations
where the notes are to be played on the guitar.  Obviously, keyboard
chords don't make the least sense in there.

-- 
David Kastrup