Proposed Doc Changes in Polyphonic music

[Carl D. Sorensen]

Here is a proposed doc addition to section 6.3.5 Collision Resolution

Just befor the heading Predefined Commands, I'd recommend the following

---
If three or more notes line up in the same column,
merge-differently-headed can't
successfully complete the merge of the two notes that should be merged.
To allow the merge to work properly, apply a \shift to the note that
should not be merged.
In the first measure of the example below, merge-differently-headed
doesn't work (the half-note head is solid).  In the second measure,
\shiftOn is applied to move the top g out of the column, and
merge-differently-headed works properly.


%%%% Begin .ly snippet
% \shiftXxx can be used to avoid "warning: too many clashing note
columns"


\version "2.10.5"  %Windows XP

\paper {indent = 0\mm ragged-right = ##t}

\relative c' {
    \override Staff.NoteCollision #'merge-differently-headed = ##t 
    << {d=''2   g2 } \\ 
       {\stemNeutral d=''8 c8 r4 e,8 c'8 r4 } \\ 
       { \voiceFour e,,2 e'2} 
    >>
    << {d=''2 \shiftOn  g2 } \\ 
       {\stemNeutral d=''8 c8 r4 e,8 c'8 r4 } \\ 
       { \voiceFour e,,2 e'2} 
    >>
}
%%%%  end of .ly snippet.

---

Also, in the Predefined Commands part of section  6.3.5 Collision
resolution, the first sentence should read "these commands specify the
degree to which chords of the current voice should be shifted." ISO
"these commands specify in what chords of the current voice should be
shifted."

--

Immediately before 6.3.5 Collision Resolution, the following text could
be added:


In some instances of complex polyphonic music, you may need additional
voices to avoid collisions between notes.  Additional voices are added
by defining an identifier, as shown below

voiceFive = #(context-spec-music (make-voice-props-set 4) 'Voice)

<< { \voiceOne g''4 ~  \stemDown g32[ f( es d c b a b64 )g] } \\ { 
\voiceThree  b4} \\ { \voiceFive d,} \\ { \voiceTwo g,}\\>>

---

Graham, I've greatly admired your work on the docs.  Now I'm even more
impressed, given that you can work on the docs during momentary pauses
in FFT lectures!

Carl Sorensen

Carl D. Sorensen
Associate Professor
Department of Mechanical Engineering
Brigham Young University
Provo, UT 84602
801-422-6397     Fax 801-422-0516