Fw: [PATCH] Eliminate accidental power chords in musicxml2ly.

[Johan Vromans]

Forwarded to bug-lilypond on request.

The patch is to address the issue that musicxml2ly generates improper
code for minor chords.

Begin forwarded message:

Date: Thu, 18 Aug 2016 13:38:21 +0200
From: Johan Vromans <address@hidden>
To: David Kastrup <address@hidden>
Subject: Re: [PATCH] Eliminate accidental power chords in musicxml2ly.


Hi David,

On Thu, 18 Aug 2016 07:10:45 +0200
David Kastrup <address@hidden> wrote:

> > I'll prepare a better solution, which involves changing the way
> > ChordNameEvent (musicexp.py) handles modifications, but I'm going to
> > sleep first. Stay tuned.    
> 
> The 5 probably was a "lazy fix".  You could probably replace it by 3.5
> but, well, I think I'd prefer a less ugly solution if you can reasonably
> come up with one.  

Main reason I do not want the 3.5 workaround is that I wouldn't want my
major chords to look like c4:3.5...

Attached is a new patch. It patches scripts/musicxml2ly as before, with
r'{}' for a major chord.
The solutions for the invalid combinations are provided in
python/musicexp.py. A colon is added if a colon-less chord (i.e., major)
has modifications. Adding additions checks for a trailing digit, if none,
the leading period is omitted. Note that the changes in python/musicexp.py
are harmless to an un-patched scripts/musicxml2ly.

Also attached are chords.xml, a sheet of many chords based on the chart
from NR A.1, and chords.ly, the desired output after conversion. There are
a few discrepancies between the output from chords.ly and the chart from NR
A.1, but these occur in very weird chords so I consider these harmless.

Regards,
        Johan

0001-Eliminate-accidental-power-chords-in-musicxml2ly.patch
Description: Text Data

chords.xml
Description: application/xml

chords.ly
Description: Text Data