+@cindex automatic part combining
+@cindex part combiner
+
+Automatic part combining is used to merge two parts of music onto on
+staff in an intelligent way. It is aimed primarily at typesetting Hymns
+and orchestral scores. When the two parts are identical for a period of
+time, only one is shown. In places where the two parts differ, stem
+directions are set automatically. Also, soli and @emph{a due} parts can be
+identified and marke.
+
+The syntax for part combining is
+
+@example
+ \partcombine @var{context} @var{musicexpr1} @var{musicexpr2}
+@end example
+
+where the pieces of music @var{musicexpr1} and @var{musicexpr2} will be
+combined into one context @var{context}. The names of the music
+expressions must start with the prefixes @code{one} and @code{two}.
+
+[Name of music expressions? is that context name? ]
+
+The most useful function of the part combiner to combining threads into
+one voice, as common for wind parts in orchestral scores:
+
+@lilypond[verbatim,singleline,fragment]
+ \context Staff <
+ \context Voice=one \partcombine Voice
+ \context Thread=one \relative c'' {
+ g a b r
+ }
+ \context Thread=two \relative c'' {
+ g r2 f4
+ }
+ >
+@end lilypond
+
+Notice that the first @code{g} appears only once, although it was
+specified twice (once in each Thread). Also note that stem, slur and tie
+directions are set automatically, depending whether there is a solo or
+unisono. The Thread called @code{one} always gets up stems, and "solo",
+while @code{two} always gets down stems and "Solo II".
+
+If you just want the splitting of Threads and setting of directions, and
+not the textual markings, you may set the property @var{soloADue} to
+false. This mode can be used to set hymns:
+
+@lilypond[verbatim,singleline,fragment]
+ \context Staff <
+ \property Staff.soloADue = ##f
+ \context Voice=one \partcombine Voice
+ \context Thread=one \relative c'' {
+ b4 a c g
+ }
+ \context Thread=two \relative c'' {
+ d,2 a4 g'
+ }
+ >
+@end lilypond
+
+There are a number of other properties that you can use to tweak
+the behavior of part combining, refer to the automatically generated
+documentation. Look for @code{Thread_devnull_engraver}
+@code{Voice_devnull_engraver} and @code{A2_engraver}.
+
+@refbugs
+
+In @code{soloADue} mode, when the two voices play the same notes on and
+off, the part combiner may typeset @code{a2} more than once in a
+measure.
+
+@lilypond[fragment,singleline]
+ \context Staff <
+ \context Voice=one \partcombine Voice
+ \context Thread=one \relative c'' {
+ c b c b c a c a
+ }
+ \context Thread=two \relative c'' {
+ b b b b f a f a
+ }
+ >
+@end lilypond
+
+@cindex @code{Thread_devnull_engraver}
+@cindex @code{Voice_engraver}
+@cindex @code{A2_engraver}
+
+@node Hara-kiri staffs
+@subsection Hara-kiri staffs
+
+In orchestral scores, staffs that only have rests are usually removed.
+This saves some space. LilyPond also supports this through the
+hara-kiri@footnote{Hara kiri, also called Seppuku, is the ritual suicide
+of the Japanese Samourai warriors.} staff. This staff commits suicide
+when it finds itself to be empty after the line-breaking process---note
+that it will not disappear when it contains normal rests, you must use
+multi measure rests.
+
+The hara kiri staff is specialized version of the Staff context. It is
+available as the context identifier @code{\HaraKiriStaffContext}.
+Observe how the second staff in this example disappears in the second
+line.
+
+@lilypond[verbatim]
+\score {
+ \notes \relative c' <
+ \context Staff = SA { e4 f g a \break c1 }
+ \context Staff = SB { c4 d e f \break R1 }
+ >
+ \paper {
+ linewidth = 6.\cm ;
+ \translator { \HaraKiriStaffContext }
+ }
+}
+@end lilypond