Moving notes in a chord to the opposite side of the stem?

[Paul Morris]

Hello,  Is there a way to manually move some of the notes in a chord to the opposite side of the stem, overriding the default placement? 

I have looked through the docs and did not find a simple way to do this (the NoteColumn #'force-hshift property only works with notes in different voices, and trying to \override NoteHead #'X-offset  within a chord just returned an error).  The best thing I came up with was this snippet:
http://lsr.dsi.unimi.it/LSR/Item?id=505

Following its example I was able to get the results I needed by doing this:

shiftR = {
  \once \override Stem #'X-offset = #.6
  \once \override NoteHead #'X-offset = #.6
}

<c' e' g' >4
<< { <c' e'> } \\ { \voiceThree \shiftR g' } >>

<d' f' a'> 
<< { d' } \\ { \voiceThree  \shiftR < f' a'> } >>

See attached screenshot.  But it seems like there should be a way to do this without having to introduce another voice? Or maybe not... I realize this is a relatively obscure usage.

(Ultimately, I would like for the notes in harmonic intervals of 3 semitones or smaller to always appear on opposite sides of the stem.  But I would not know how to do that automatically, if it is even possible.)

Thanks!
-Paul

http://twinnote.org

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