Re: Chords in LilyPond

[Vaughan McAlley]

On 29 May 2017 at 09:53, Thomas Morley <address@hidden> wrote:

This sounds like you want to write a chord-analyser or probably a
better wording would be chord-interpreter.

I think it’s impractical to use chord analysis on anything but anything but simple chords. Power users like Kieren and Robert will want to tweak the output, because, as Robert showed, one set of pitches can mean more than one chord symbol.

Robert Schmaus:

which of course doesn't sound nice in the midi output. I can live with that - the midi is secondary for me,

 At the moment the chord performer has no musicality to it:

%%%%%%%%%%%%%%
\version "2.18.2"

chrds-test = \chordmode {
c4 bes c bes }

<<
  \new ChordNames \chrds-test
  \new Staff \chrds-test
>>

Does anyone actually use MIDI from the chord performer? When I'm checking choral music (ie. with well-defined lines), the MIDI output is of acceptable quality for checking for mistakes and getting an impression of the piece. Whenever I use chords, I turn them off because it's so annoying. I check a lead sheet using my limited piano skills, where the chords are voiced at least semi-acceptably. I had this issue too with Finale back in the day.

Anyway, getting the chord performer to reference the previous chord when "performing" could be possible. And a chord-bass performer could analyse a chord, find a root either from the chord's notes or its attached properties and play an acceptable bass line.

Robert Schmaus:

My point is, right now the only of distinguishing these chords is by using parts of the explicit scale in chord mode to distinguish them.
I've chosen to use

c : 7.5+     for C7(#5)
c : 7.5+.2   for C+7

Maybe it would be nice to have something like (please excuse my pseudoScheme):

\chordmode {

  \chord-modify #'(

    (root . c) ; in case of ambiguity, used by the engraver for the letter

    (suffix . "C+7") ; or whichever markup

    (bass . e,)) ; used to engrave the bass note, and by the chord-bass performer

  <ais c' gis'>4 % how the chord performer would 'perform' it
}

All of these would be overriding sensibly chosen defaults that should work fine in most use cases.

Kieren:

How do you represent polychords?

Each chord is a list of chords, usually containing one item.

Vaughan
 

chords.png
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