Slurring into another voice without breaking a beam

[Knute Snortum]

This is a little complicated to describe, but I'll give it my best shot.

The problem starts with lower notes in a chord slurring differently than the upper notes.  (See attachment Chopin-Opus-32-no-2-measure-33.)  I handled it like this:

%%% Start

\version "2.19.83"
\include "english.ly"

\relative {
  \time 12/8
  <<
    { s4. s4 \omit Stem \omit Flag \stemDown f'8_( e) s4 s4. }
    \\
    {  
      <e c'>8 <e df'> <e_~ c'>^( <e bf'> <f af>) <f bf>^(
      <e c'> <e df'>) <e_~ c'>^( <e bf'> <f af>) <af bf>
    }
  >>
}

%%% End 

This works, but is there a better way to do it without temporary voices?  The problem arises because the first two eighth notes are ending a long slur from outside the temporary voice.  I "fixed" that with a \context Voice command...

%%% Start

\version "2.19.83"
\include "english.ly"

\relative {
  \time 12/8
   c''8 <af b>( <af c> <af af'>) \context Voice = "2" { <af g'>-.( <af gf'>-.
    <g f'>-. <g e'>-. <g~ef'>-. <g d'>-. <g df'>-. <g c>-. |
  \appoggiatura { bf16 c } \stemDown <g bf>8 <g a> <g bf> <e df'> <e c'> <e g>
    <f bf> <f af> <f g> <f af> <f bf> <f b> } |
  <<
    { s4. s4 \omit Stem \omit Flag \stemDown f8_( e) s4 s4. }
    \\
    {  
      <e c'>8 <e df'>) <e_~ c'>^( <e bf'> <f af>) <f bf>^(
      <e c'> <e df'>) <e_~ c'>^( <e bf'> <f af>) <af bf>
    }
  >> |
}

%%% End

...but the problem is that it breaks the beaming,  (See attachment chopin-opus-32-no-1-measures-31-33).

So if there a better way to typesetting the slur of bottom notes in a chord, or a way to fix the beaming when the notes are in different voices?

---

Knute Snortum

(via Gmail)

Chopin-Opus-32-no-2-measure-33.png
Description: PNG image

chopin-opus-32-no-1-measures-31-33.png
Description: PNG image