Auto-beaming changes

 - add beam grouping rules for 3/8, 4/8, 6/4, 6/16,
   9/4, 9/16, 12/4, 12/16 time signatures

 - amend beam ending rules to limit lengths of
   beamed runs of 16th and 32nd notes in some
   time signatures only (these may need some
   fine-tuning with experience and feedback)

 - except for 4/4 time, where the previous beaming
   is preserved

 - amend documentation to match

diff --git a/Documentation/user/rhythms.itely b/Documentation/user/rhythms.itely
index e02d14258e5d01a72fe4637a4fe1763beb90422c..a931db3d979b5dfb78b55626b0deb6ffb9bd9071 100644 (file)
--- a/Documentation/user/rhythms.itely
+++ b/Documentation/user/rhythms.itely
@@ -1438,9 +1438,6 @@ By default, beams are inserted automatically:
 @cindex beams, setting rules for
 @cindex beams, custom rules for
 
-@funindex measureLength
-@funindex beatLength
-@funindex beatGrouping
 @funindex \autoBeamOn
 @funindex autoBeamOn
 @funindex \autoBeamOff
@@ -1452,29 +1449,11 @@ By default, beams are inserted automatically:
 @end lilypond
 
 If these automatic decisions are not satisfactory, beaming can be
-entered explicitly; see @ref{Manual beams}.  Beams must also be
-entered manually in the same way if beams are to be extended over
-rests.
-
-It is possible
-to define beaming patterns that differ from the defaults.  The
-default beaming rules for most common time signatures are defined
-in @file{scm/@/auto@/-beam@/.scm}.  If there are no beaming rules
-defined for a particular beam's duration in the time signature being
-used, its beaming is controlled by the values of three context
-properties, @code{measureLength}, @code{beatLength} and
-@code{beatGrouping}.  Both the beaming rules and the context
-properties can be overridden, see @ref{Setting automatic beam behavior}.
+entered explicitly; see @ref{Manual beams}.  Beams @emph{must} be
+entered manually if beams are to be extended over rests.
 
-
-@warning{If beams are used to indicate melismata in songs, then automatic
-beaming should be switched off with @code{\autoBeamOff} and the beams
-indicated manually.}
-
-
-@noindent
-Automatic beaming may be turned off and on with
-@code{\autoBeamOff} and @code{\autoBeamOn} commands:
+If automatic beaming is not required, it may be turned off with
+@code{\autoBeamOff} and on with @code{\autoBeamOn}:
 
 @lilypond[quote,relative=1,verbatim]
 c4 c8 c8. c16 c8. c16 c8
@@ -1484,6 +1463,13 @@ c4 c8 c8. c16 c8.
 c16 c8
 @end lilypond
 
+@warning{If beams are used to indicate melismata in songs, then
+automatic beaming should be switched off with @code{\autoBeamOff}
+and the beams indicated manually.}
+
+Beaming patterns that differ from the automatic defaults may be
+created, see @ref{Setting automatic beam behavior}.
+
 
 @predefined
 @code{\autoBeamOff},
@@ -1549,18 +1535,29 @@ Beams can collide with note heads and accidentals in other voices
 @funindex \set
 @funindex set
 
-The placement of automatic beams is determined by the rules
-described in @ref{Automatic beams}.  There are two mutually
-exclusive ways in which these rules may be modified.  The
-first, modifying the grouping of beats, applies to uncommon time
-signatures, i.e. those for which there are no predefined rules
-defining the beam end points.  The second method, modifying the
-specification of the beam end points, can be used for any time
-signature.  This second method @strong{must} be used for those time
-signatures and beam durations combinations for which beam ending
-rules are pre-defined, unless these have all been reverted.  There
-are predefined rules for time signatures of 3/2, 3/4, 4/4, 2/4,
-4/8, 4/16, 6/8, 9/8 and 12/8.
+There are two types of beaming rules:  @emph{beam-grouping}
+rules and @emph{beam-ending} rules.  Beam-grouping rules are the
+simplest, but are over-ridden by any beam-ending rules which apply.
+
+The placement of automatic beams is determined by applying the
+following rules in order:
+
+@itemize
+
+@item If a manual beam is specified with @code{[..]} set the beam
+as specified, otherwise
+
+@item if @code{\autoBeamOff} is in force do not beam, otherwise
+
+@item if a beam-ending rule applies use it to determine the valid
+places where beams may end, otherwise
+
+@item if a valid (see below) beat-grouping rule applies use it to
+group notes with beams, otherwise
+
+@item use the value of @code{beatLength} to group notes with beams
+
+@end itemize
 
 @i{@strong{Modifying the grouping of beats}}
 
@@ -1570,8 +1567,14 @@ controlled by three context properties:
 @code{measureLength}, @code{beatLength} and @code{beatGrouping}.
 These properties may be set in the @code{Score}, @code{Staff} or
 @code{Voice} contexts to delimit their scope.  The default values
-are set while processing @code{\time} commands, so the @code{\set}
-commands must be placed after all @code{\time} commands.
+are set while processing @code{\time} commands, so any @code{\set}
+commands to modify their value must be placed after all @code{\time}
+commands.
+
+@warning{These three properties become effective for a particular
+beam @strong{only} if there are no beam-ending rules predefined for
+that beam's duration in the time signature in use, or if these
+beam-ending rules have all been reverted.}
 
 These determine the beaming as follows:
 
@@ -1591,11 +1594,6 @@ the end points of beams.
 
 @end itemize
 
-@warning{These three properties become effective for a particular
-beam @strong{only} if there are no beam-ending rules predefined for
-that beam's duration in the time signature in use, or if these
-beam-ending rules have all been reverted.}
-
 By default the @code{measureLength} and @code{beatLength} are
 derived from the time signature set by the @code{\time} command.
 The @code{measureLength} is set to be exactly the same length as
@@ -1606,7 +1604,8 @@ of the time signature.
 The default value of @code{beatGrouping} is taken from a table in
 @file{scm/@/music@/-functions@/.scm}.  To find this, see
 @rlearning{Other sources of information}.  It defines the beat
-grouping for 5/8, 6/8, 8/8, 9/8 and 12/8 time signatures.
+grouping for 3/8, 4/8, 5/8, 8/8, and all the common compound time
+signatures.
 
 Both @code{measureLength} and @code{beatLength} are @i{moments},
 units of musical duration.  A quantity of type @i{moment} is
@@ -1643,20 +1642,21 @@ beats in each group.
 
 @strong{@i{Modifying the beam end points}}
 
-In common time signatures, automatic beams can start on any note
-but can end at only a few positions within the measure, namely at
-durations specified by the properties in @code{autoBeamSettings}.
-These properties consist of a list of rules defining where beams can
-end.  The default @code{autoBeamSettings} rules are defined in
-@file{scm/@/auto@/-beam@/.scm}.  To find this, see
+Beam-ending rules are required when beams of different durations are
+to end at different points within the measure.  For example, it may
+be desirable for eighth-note beams in 4/4 time to end only at the
+end of the measure or half-way through it, but for sixteenth-note
+beams to end at quarter note positions to avoid overly long beamed
+runs.  The rules work as follows:
+
+Automatic beams can start on any note but can end at only a few
+positions within the measure, namely at positions specified by the
+properties in @code{autoBeamSettings}.  These properties consist of
+a list of rules defining where beams can end.  The default
+@code{autoBeamSettings} rules are defined in
+@file{scm/@/auto@/-beam@/.scm}.  To find this file, see
 @rlearning{Other sources of information}.
 
-This method @strong{must} be used for the time signatures for which
-beam-ending rules are defined by default, unless these have all
-been reverted.  It is also particularly suitable for many other time
-signatures if the time signature of the measures changes frequently,
-or if the beaming should be different for different beam durations.
-
 In order to add a rule to the list, use
 
 @example
@@ -1762,8 +1762,8 @@ possible interference, because the beam endings defined there will
 still apply in addition to your own.}
 
 Any unwanted or conflicting default endings must be reverted for
-your time signature(s).  Existing auto-beam rules are removed by
-using
+your time signature(s).  Existing default or user-defined
+beam-ending rules are removed by using
 
 @example
 #(revert-auto-beam-setting

diff --git a/scm/auto-beam.scm b/scm/auto-beam.scm
index 6479969eb8deb1c2b39b2387f8da0600df5ceb1f..8940c232fbd825c3ae1a34bcce3de53c7399140b 100644 (file)
--- a/scm/auto-beam.scm
+++ b/scm/auto-beam.scm
@@ -24,95 +24,93 @@
 (define-public default-auto-beam-settings
   `(
     ;; in 2 2 time:
-    ;;  use beatLength for all except 32nd notes
-    ;;  end beams with 32nd notes each 1 4 beat
+    ;;   use beatLength for all except 32nd notes
+    ;;   end beams with 32nd notes each 1 4 beat
 
     ((end 1 32 2 2) . ,(ly:make-moment 1 4))
     ((end 1 32 2 2) . ,(ly:make-moment 2 4))
     ((end 1 32 2 2) . ,(ly:make-moment 3 4))
 
-    ;; in 3 2 time:
-    ;;   use beatLength for all except 16th and 32nd notes
-    ;;   end beams with 16th notes each 1 4 beat
-    ;;   end beams with 32nd notes each 1 8 beat
+    ;; in 2 4, 2 8 and 2 16 time:
+    ;;   use beatLength
 
-    ((end 1 16 3 2) . ,(ly:make-moment 1 4))
-    ((end 1 16 3 2) . ,(ly:make-moment 2 4))
-    ((end 1 16 3 2) . ,(ly:make-moment 3 4))
-    ((end 1 16 3 2) . ,(ly:make-moment 4 4))
-    ((end 1 16 3 2) . ,(ly:make-moment 5 4))
-
-    ((end 1 32 3 2) . ,(ly:make-moment 1 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 2 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 3 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 4 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 5 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 6 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 7 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 8 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 9 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 10 8))
-    ((end 1 32 3 2) . ,(ly:make-moment 11 8))
-
-    ;; in 2 4 time:
+    ;; in 3 2 time:
     ;;   use beatLength for all except 32nd notes
-    ;;   end beams with 32nd notes each 1 8 beat
+    ;;   end beams with 32nd notes each 1 4 beat
 
-    ((end 1 32 2 4) . ,(ly:make-moment 1 8))
-    ((end 1 32 2 4) . ,(ly:make-moment 2 8))
-    ((end 1 32 2 4) . ,(ly:make-moment 3 8))
+    ((end 1 32 3 2) . ,(ly:make-moment 1 4))
+    ((end 1 32 3 2) . ,(ly:make-moment 2 4))
+    ((end 1 32 3 2) . ,(ly:make-moment 3 4))
+    ((end 1 32 3 2) . ,(ly:make-moment 4 4))
+    ((end 1 32 3 2) . ,(ly:make-moment 5 4))
 
-    ;; in 3 4 time:
-    ;;   override beatLength which would end beams at 1 4 beats
-    ;;   end beams with 16th notes each 1 4 beat
-    ;;   end beams with 32nd notes each 1 8 beat
+    ;; in 3 4, 3 8 and 3 16 time:
+    ;;   use beatLength
 
-    ((end * * 3 4) . ,(ly:make-moment 3 4))
-    ((end 1 16 3 4) . ,(ly:make-moment 1 4))
-    ((end 1 16 3 4) . ,(ly:make-moment 2 4))
-    ((end 1 32 3 4) . ,(ly:make-moment 1 8))
-    ((end 1 32 3 4) . ,(ly:make-moment 2 8))
-    ((end 1 32 3 4) . ,(ly:make-moment 3 8))
-    ((end 1 32 3 4) . ,(ly:make-moment 4 8))
-    ((end 1 32 3 4) . ,(ly:make-moment 5 8))
-
-    ;; in common time:
-    ;;   override beatLength which would end beams at 1 4 beats
-    ;;   end all beams at 1 2 beat
-    ;;   end beams with 8th triplets each 1 4 beat
+    ;; in 4 2 time:
+    ;;   use beatLength for all except 16th and 32nd notes
     ;;   end beams with 16th notes each 1 4 beat
     ;;   end beams with 32nd notes each 1 8 beat
 
-    ((end * * 4 4) . ,(ly:make-moment 1 2))
-
-    ((end 1 12 4 4) . ,(ly:make-moment 1 4))
-    ((end 1 12 4 4) . ,(ly:make-moment 3 4))
-
-    ((end 1 16 4 4) . ,(ly:make-moment 1 4))
-    ((end 1 16 4 4) . ,(ly:make-moment 3 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 1 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 2 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 3 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 4 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 5 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 6 4))
+    ((end 1 16 4 2) . ,(ly:make-moment 7 4))
+
+    ((end 1 32 4 2) . ,(ly:make-moment 1 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 2 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 3 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 4 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 5 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 6 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 7 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 8 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 9 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 10 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 11 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 12 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 13 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 14 8))
+    ((end 1 32 4 2) . ,(ly:make-moment 15 8))
+
+    ;; in 4 4 (common) time:
+    ;;  use beatLength for all except 32nd notes:
+    ;;  end beams with 32nd notes each 1 8 beat
+
+    ((end 1 8 4 4) . ,(ly:make-moment 1 2))
 
     ((end 1 32 4 4) . ,(ly:make-moment 1 8))
     ((end 1 32 4 4) . ,(ly:make-moment 2 8))
     ((end 1 32 4 4) . ,(ly:make-moment 3 8))
+    ((end 1 32 4 4) . ,(ly:make-moment 4 8))
     ((end 1 32 4 4) . ,(ly:make-moment 5 8))
     ((end 1 32 4 4) . ,(ly:make-moment 6 8))
     ((end 1 32 4 4) . ,(ly:make-moment 7 8))
 
-    ;; in 3 8 time:
-    ;;   override beatLength which would end beams at 1 8 beats
+    ;; in 4 8 and 4 16 time:
+    ;;   use beatLength
 
-    ((end * * 3 8) . ,(ly:make-moment 3 8))
+    ;; in 6 4 time:
+    ;;   use beatGrouping for all except 16th, 32nd notes
+    ;;   end beams with 16th or 32nd notes each 1 4 beat
 
-    ;; in 4 8 time
-    ;;   override beatLength which would end beams at 1 8 beats
-    ;;   end all beams at 1 4 beat
-    ;;   end beams with 32nd notes each 1 8 beat
 
-    ((end * * 4 8) . ,(ly:make-moment 1 4))
-    ((end 1 32 4 8) . ,(ly:make-moment 1 8))
-    ((end 1 32 4 8) . ,(ly:make-moment 3 8))
+    ((end 1 16 6 4) . ,(ly:make-moment 1 4))
+    ((end 1 16 6 4) . ,(ly:make-moment 2 4))
+    ((end 1 16 6 4) . ,(ly:make-moment 3 4))
+    ((end 1 16 6 4) . ,(ly:make-moment 4 4))
+    ((end 1 16 6 4) . ,(ly:make-moment 5 4))
+
+    ((end 1 32 6 4) . ,(ly:make-moment 1 4))
+    ((end 1 32 6 4) . ,(ly:make-moment 2 4))
+    ((end 1 32 6 4) . ,(ly:make-moment 3 4))
+    ((end 1 32 6 4) . ,(ly:make-moment 4 4))
+    ((end 1 32 6 4) . ,(ly:make-moment 5 4))
 
-    ;; in 6 8, 9 8 and 12 8 time:
+    ;; in 6 8 time:
     ;;   use beatGrouping for all except 32nd notes
     ;;   end beams with 32nd notes each 1 8 beat
 
@@ -122,6 +120,35 @@
     ((end 1 32 6 8) . ,(ly:make-moment 4 8))
     ((end 1 32 6 8) . ,(ly:make-moment 5 8))
 
+    ;; in 6 16 time:
+    ;;   use beatGrouping
+
+    ;; in 9 4 time:
+    ;;   use beatGrouping for all except 16th, 32nd notes
+    ;;   end beams with 16th or 32nd notes each 1 4 beat
+
+    ((end 1 16 9 4) . ,(ly:make-moment 1 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 2 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 3 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 4 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 5 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 6 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 7 4))
+    ((end 1 16 9 4) . ,(ly:make-moment 8 4))
+
+    ((end 1 32 9 4) . ,(ly:make-moment 1 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 2 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 3 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 4 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 5 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 6 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 7 4))
+    ((end 1 32 9 4) . ,(ly:make-moment 8 4))
+
+    ;; in 9 8 time:
+    ;;   use beatGrouping for all except 32nd notes
+    ;;   end beams with 32nd notes each 1 8 beat
+
     ((end 1 32 9 8) . ,(ly:make-moment 1 8))
     ((end 1 32 9 8) . ,(ly:make-moment 2 8))
     ((end 1 32 9 8) . ,(ly:make-moment 3 8))
@@ -131,6 +158,41 @@
     ((end 1 32 9 8) . ,(ly:make-moment 7 8))
     ((end 1 32 9 8) . ,(ly:make-moment 8 8))
 
+    ;; in 9 16 time
+    ;;   use beatGrouping
+
+    ;; in 12 4 time:
+    ;;   use beatGrouping for all except 16th, 32nd notes
+    ;;   end beams with 16th or 32nd notes each 1 4 beat
+
+    ((end 1 16 12 4) . ,(ly:make-moment 1 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 2 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 3 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 4 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 5 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 6 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 7 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 8 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 9 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 10 4))
+    ((end 1 16 12 4) . ,(ly:make-moment 11 4))
+
+    ((end 1 32 12 4) . ,(ly:make-moment 1 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 2 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 3 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 4 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 5 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 6 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 7 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 8 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 9 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 10 4))
+    ((end 1 32 12 4) . ,(ly:make-moment 11 4))
+
+    ;; in 12 8 time:
+    ;;   use beatGrouping for all except 32nd notes
+    ;;   end beams with 32nd notes each 1 8 beat
+
     ((end 1 32 12 8) . ,(ly:make-moment 1 8))
     ((end 1 32 12 8) . ,(ly:make-moment 2 8))
     ((end 1 32 12 8) . ,(ly:make-moment 3 8))
@@ -143,10 +205,8 @@
     ((end 1 32 12 8) . ,(ly:make-moment 10 8))
     ((end 1 32 12 8) . ,(ly:make-moment 11 8))
 
-    ;; in 4 16 time
-    ;;   end all beams each 1 8 beat
-
-    ((end * * 4 16) . ,(ly:make-moment 1 8))
+    ;; in 12 16 time:
+    ;;   use beatGrouping
 
     ))
 

diff --git a/scm/music-functions.scm b/scm/music-functions.scm
index 42a08cc344c0ec8731d3c1f428f0d7a06a6a5c4b..de8b5973fb67f0101a741a58c2d51803187707e2 100644 (file)
--- a/scm/music-functions.scm
+++ b/scm/music-functions.scm
@@ -479,17 +479,29 @@ of beat groupings "
     "Some standard subdivisions for time signatures."
     (let*
        ((key (cons num den))
-        (entry (assoc key '(((6 . 8) . (3 3))
-                        ((5 . 8) . (3 2))
-                        ((9 . 8) . (3 3 3))
-                        ((12 . 8) . (3 3 3 3))
-                        ((8 . 8) . (3 3 2))
-                        ))))
+        (entry (assoc key '(
+               ; Simple time signatures
+               (( 3 .  8) . (3))
+               (( 4 .  8) . (2 2))
+               ; Compound time signatures
+               (( 6 .  4) . (3 3))
+               (( 6 .  8) . (3 3))
+               (( 6 . 16) . (3 3))
+               (( 9 .  4) . (3 3 3))
+               (( 9 .  8) . (3 3 3))
+               (( 9 . 16) . (3 3 3))
+               ((12 .  4) . (3 3 3 3))
+               ((12 .  8) . (3 3 3 3))
+               ((12 . 16) . (3 3 3 3))
+               ; Some common irregular time signatures
+               (( 5 .  8) . (3 2))
+               (( 8 .  8) . (3 3 2))
+               ))))
 
       (if entry
          (cdr entry)
-         '())))    
-  
+         '())))
+
   (let* ((set1 (make-property-set 'timeSignatureFraction (cons num den)))
         (beat (ly:make-moment 1 den))
         (len  (ly:make-moment num den))