Re: Chords in LilyPond

[Thomas Morley]

Hi Matthew,

2017-05-25 3:39 GMT+02:00  <address@hidden>:
> On Wed, 24 May 2017, Charles Winston wrote:
>> I’m participating in the Google Summer of Code working on improving 
>> LilyPond’s internal representation of chords. The goal here is to create a 
>> data structure that will represent a chord’s semantics beyond just a list of 
>> notes in the chord. The current representation contains almost no 
>> information other than a list of notes, and we want to change this to 
>> include other semantic information, i.e. the root, quality, extensions. The 
>> current representation causes the chord naming process to infer the correct 
>> name from only the notes in the chord, which can create some problems—it 
>> would be much better to maintain the information provided by the user in 
>> chord mode about the semantics of the chord through to the naming process. 
>> Here is a rough list of semantic information I believe should be included in 
>> the data structure:
>
> Correctly printing chord names - and specifically "Why doesn't the output
> match what I typed?" - is a huge problem for users, and is a recurring
> thread on this list, so I certainly think improvements there would be a
> good thing.

I vaguely remember such threads.
Though, could you give some examples (or links) so it is present here as well?

>
> What I think is most needed is a chord-naming mode that *just prints what
> the user typed*, formatted with the fonts, spacing, and so on that we
> expect for chord names

Well, that's one of the major problems.
There seems to be no "we", even my expectations may differ from yours.

And a chord-naming mode that *just prints what the user typed* is
currently not specific enough for me.
Could you give a pseudo-code-example demonstrating something for which
current LilyPond fails?

Something at the line of

\new ChordNames \chord-input-mode { c7/des }
-> C⁷/D♭

This is not a good example, because current LilyPond can do this
without problems:
\new ChordNames \chordmode { c1:7/des  }
But you may get what I mean.


Cheers,
  Harm