Re: Multiple tensions in Chord Mode

[lilypond]

On Mon, May 28, 2012 at 09:48:29AM -0400, Louis Guillaume wrote:
> 
> There is, however, one thing that I find impossible, that is, having two 
> of the same tension in the chord symbol expression. There is a single 
> case I can think of and that is having both flat-nine and sharp-nine on 
> a dominant chord. e.g.
> 
>    In chord mode:
> 
>      c:7.9-.9+
> 
>    In regular markup:
> 
>      <c e g bes des' dis'>
> 
> Both of these produce a chord symbol AND chord without the flat-nine. It 
> seems to only accommodate one 9th, and uses the last one encountered.
> 
> Is there a way to do work around this?
> 
> Louis

Hi, Louis.

If I may start with a bit of humble philosophy, when I see a flat
9 especially, I almost always conclude that the tonality will
include a sharp 9 as well, simply because of the dissonance that
would result from having the flat 9 competing against an
unaltered 9.  Not to say that it could never happen, it just
strikes me as being rare.  This doesn't necessarily work the
other way around.  A sharp 9 chord to me would normally imply a
normal 9 also, unless inspection of the melody or harmony
suggests a flat 9 would be more appropriate, in which case I'll
grumble that the arranger should have written a flat 9.

In summary, IMHO:

flat 9 = flat 9 and usually sharp 9 also
sharp 9 = sharp 9 and usually natural 9 (or 2)

If you want a flat 9 sharp 9 chord, consider using a flat 9 and
leaving the sharp 9 implied.  This is especially appropriate if
the key signature implies a sharp 9 (C7 b9 in key of Db, Bb or Ab
for example)

IMHO, this situation also arises around flat fifths -- a flat
fifth would almost always cause me to assume a sharp fifth as
well.  C7 b5 often implies a whole-tone scale (c d e ges aes bes
c).  However, I don't make this assumption about sharp 11 chords.
I assume that sharp 11 chords are chosen to make the fourth tone
of the mode be only a half step away from the perfect fifth,
Lydian-style.

Anyway, having tried my best to talk you out of it, :) I can
understand your desire to explicitly call out both alterations
when necessary.  I experimented quite a bit with this and learned
a lot about the extent of the gap in my knowledge about lilypond
chordmode and chord naming.

I use jazz-chords.ily instead of pop-chords.ly, but ....

Look in your pop-chords.ly file for a chord defined as 
<c e g bes cis' dis'>    If you find it, comment out that chord
markup.  If you don't find it, double check for alternate
enharmonic spellings.  If you still can't find it, perhaps it's
not in pop-chords.ly.

In my jazz-chords.ily I inserted this instead, with a slight
spelling difference of des here instead of cis above:

        <c e g bes des' dis'>-\markup\jcRaise{ "7(" \jcFlat "9" \jcSharp "9)" }

For pop-chords.ly, the \jc* functions don't exist, so use this 
in pop-chords.ly:

        <c e g bes des' dis'>-\markup { "7" \chordFlat "9" \chordSharp "9" }

Now the strangest thing that I ran into was that I do not know
how (and could not find a way) to describe those notes in
\chordmode.  As your message suggested, it appears that chordmode
can handle only one alteration per scale degree, and it seems
that a later alteration overrides any earlier alteration for a given
scale tone.  Further strangeness arose when I realized that
spelling the same chord pitches in different order changes the
way the chord markup is selected.

However, the following snippet produces the correct markup,
although the inability to use a \chordmode representation of
those notes may prove to be inconvenient.  I don't have the
expertise to say whether the fact that identical chord pitches
(shown as identically engraved chords) specified in a different
sequence causes the chord naming functions to assign different
markup to the chord.  Could be seen as a feature by some, I
suppose.

I hope this helps.  It was an interesting learning experience.

Jim



\version "2.15.38"

\include "jazz-chords.ily"

Chords = {

% two ways of invoking a C7 flat 9
      <c' e' g' bes' des''>1
      \chordmode { c1:7.9- }
      \bar "||"

% four attempts at invoking a C7 flat 9 sharp 9

% lilypond appears to figure this one out itself, perhaps based
% on code in or near ly/chord-modifiers-init.ly.  However, it
% calls it a #9 b9 chord, despite the fact that the flat 9 is
% stipulated first (and is the lower of the two pitches).
      <c' e' g' bes' des'' dis''>1

% the first altered 9th gets 'overwritten' by the second altered 9th
      \chordmode { c1:7.9-9+ }

% ... regardless of order, the second one overrules the first one
      \chordmode { c1:7.9+9- }
      \bar "||"

% changing the order of the notes, putting the dis before the des
      <c' e' g' bes' dis'' des''>1
% no known way to describe this in \chordmode

} % chords


\score {
  <<
    \new ChordNames { \Chords }

    \new Staff {
      \key f \major
      \numericTimeSignature
      \time 4/4
      \Chords
    } % Staff
  >>
} % score

c7-flat9-sharp9.png
Description: PNG image