For MIDI \unfoldRepeats, explicit \repeat volta in all voices is awkward

[Mark D . Blackwell]

> I am not top-posting

For MIDI \unfoldRepeats, explicit \repeat volta in all voices is awkward 

Regarding MIDI output and \unfoldRepeats, LilyPond (I checked version 2.17.9)
currently follows this statement in the documentation:

http://lilypond.org/doc/v2.17/Documentation/notation/repeats-in-midi

"In scores containing multiple voices, unfolding of repeats in MIDI output will
only occur correctly if each voice contains fully notated repeat indications."

I write to complain (or suggest) because:

Requiring the users to add \repeat volta to all the voices is telling them to
violate the DRY (don't repeat yourself) principle.

This is especially awkward for choral works. Even when printing individual
instrumental parts, it's far easier for a user to include a Dynamics context (as
below).

As background (as you may know), in a score's stack of staves, any single voice
(such as a \new Dynamics staff-like context) can successfully contain, without
duplication in other voices, all the work's LilyPond statements of the kinds:

* \repeat volta;
* \time signatures; and
* Special barlines such as \bar "|.".

and the printed output won't break. A clear example of this, for a typical
choral work, is:

workTempo = {
  \tempo "Adagio" 2 = 68
  \time 2/2
  \repeat volta 2 { \repeat unfold 2 s1 }
  \bar "|."
}
work = <<
    \new Dynamics \workTempo
    \new ChoirStaff << ... >>
    \new PianoStaff << ... >>
>>
\book {
  \score \work
}