+Snippets: @lsrdir{Rhythms,Rhythms}
+
+Internals Reference: @internalsref{Note_heads_engraver},
+@internalsref{Completion_heads_engraver},
+@internalsref{Forbid_line_break_engraver}.
+
+
+
+
+
+@node Beams
+@subsection Beams
+
+@menu
+* Automatic beams::
+* Setting automatic beam behavior::
+* Manual beams::
+* Feathered beams::
+@end menu
+
+@node Automatic beams
+@unnumberedsubsubsec Automatic beams
+
+By default, beams are inserted automatically:
+
+@cindex beams, manual
+@cindex manual beams
+
+@lilypond[quote,ragged-right,fragment,verbatim,relative=2]
+\time 2/4 c8 c c c
+\time 6/8 c c c c8. c16 c8
+@end lilypond
+
+If these automatic decisions are not satisfactory, beaming can be
+entered explicitly; see @ref{Manual beams}. It is also possible
+to define beaming patterns that differ from the defaults; see
+@ref{Setting automatic beam behavior}. The default beaming rules
+are defined in @file{scm/@/auto@/-beam@/.scm}.
+
+@cindex autoBeamOn
+@cindex autoBeamOff
+
+@noindent
+Automatic beaming may be turned off and on with
+@code{\autoBeamOff} and @code{\autoBeamOn} commands:
+
+@lilypond[quote,ragged-right,fragment,relative=1,verbatim]
+c4 c8 c8. c16 c8. c16 c8
+\autoBeamOff
+c4 c8 c8. c16 c8.
+\autoBeamOn
+c16 c8
+@end lilypond
+
+
+@commonprop
+
+Beaming patterns may be altered with the @code{beatGrouping} property,
+
+@lilypond[quote,verbatim,relative=2,fragment,ragged-right]
+\time 5/16
+\set beatGrouping = #'(2 3)
+c8[^"(2+3)" c16 c8]
+\set beatGrouping = #'(3 2)
+c8[^"(3+2)" c16 c8]
+@end lilypond
+
+The beams of consecutive 16th (or shorter) notes are, by default,
+not sub-divided. That is, the three (or more) beams stretch
+unbroken over entire groups of notes. This behaviour can
+be modified to sub-divide the beams into sub-groups by setting
+the property @code{subdivideBeams}. When set, multiple beams
+will be sub-divided at intervals defined by the current value of
+@code{beatLength} by reducing the multiple beams to just one beam
+between the sub-groups. Note that @code{beatLength} lives in the
+@code{Score} context and defaults to a quarter note. It must be
+set to a fraction giving the duration of the beam sub-group
+using the @code{make-moment} function, as shown here:
+
+@lilypond[fragment,ragged-right,quote,relative=2,verbatim]
+c32[ c c c c c c c]
+\set subdivideBeams = ##t
+c32[ c c c c c c c]
+% Set beam sub-group length to an eighth note
+\set Score.beatLength = #(ly:make-moment 1 8)
+c32[ c c c c c c c]
+% Set beam sub-group length to a sixteenth note
+\set Score.beatLength = #(ly:make-moment 1 16)
+c32[ c c c c c c c]
+@end lilypond
+@funindex subdivideBeams
+
+@noindent
+For more information about @code{make-moment}, see
+@ref{Time administration}.
+
+@funindex breakable
+@cindex break, line
+@cindex line breaks
+
+Line breaks are normally forbidden when beams cross bar lines.
+This behavior can be changed by setting the @code{breakable}
+property: @code{\override Beam #'breakable = ##t}.
+
+@lilypond[ragged-right,relative=2,fragment,verbatim,quote]
+\override Beam #'breakable = ##t
+c8 \repeat unfold 15 {c[ c] } c
+@end lilypond
+
+@cindex beams and line breaks
+@cindex beams, kneed
+@cindex kneed beams
+@cindex auto-knee-gap
+
+Kneed beams are inserted automatically when a large gap is
+detected between the note heads. This behavior can be tuned
+through the @code{auto-knee-gap} property. A kneed beam is
+drawn if the gap is larger than the value of
+@code{auto-knee-gap} plus the width of the beam object (which
+depends on the duration of the notes and the slope of the beam).
+By default @code{auto-knee-gap} is set to 5.5 staff spaces.
+
+@lilypond[fragment,ragged-right,quote,verbatim]
+f8 f''8 f8 f''8
+\override Beam #'auto-knee-gap = #6
+f8 f''8 f8 f''8
+@end lilypond
+
+
+@seealso
+
+Notation Reference: @ref{Manual beams}, @ref{Setting automatic beam behavior}.
+
+Snippets: @lsrdir{Rhythms,Rhythms}
+
+Internals Reference: @internalsref{Beam}.
+
+
+@refbugs
+
+Automatically kneed cross-staff beams cannot be used together with
+hidden staves. See @ref{Hiding staves}.
+
+Beams can collide with note heads and accidentals in other voices