Re: Chords in LilyPond

[mskala]

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.

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 - not translating it to an "internal
representation" of notes plus extra data as LilyPond "music" at all.  But
I was shouted down last time I proposed that, I think by people who
thought I had claimed it would solve all possible obscure problems for
imaginable hypothetical users.  As I made clear, it would only solve the
main problem of 99% of relevant users who actually exist, and that wasn't
enough to satisfy the list.

Failing a direct "print what I typed" mode, adding a lot of extra data to
the internal representation while keeping the current framework is the
hard way to get the input to match the output, but it'd be an improvement
and we need an improvement.

-- 
Matthew Skala
address@hidden                 People before principles.
http://ansuz.sooke.bc.ca/