doesn't matter where you make new lines in the source file.
The example also indicates that a piece of music written in a high
-register needs lots of quotes. This makes the input a bit unreadable,
+register needs lots of quotes. This makes the input less readable,
and is therefore also a potential source of errors.
@separate
@code{point-and-click} to the value @var{line-column-location} (which
itself is a Scheme procedure).
-Editing input files can be quite complicated if you're working with
+Editing input files can be complicated if you're working with
large files: if you're digitizing existing music, you have to
synchronize the .ly file, the sheet music on your lap and the sheet
music on the screen. The point-and-click mechanism makes it easy to
c8
\translator Staff = up
\stemDown
- c'8 }
+ c'8 @}
@end example
Voices can switch between staves. Here you see two staff switching
commands. The first one moves to the lower staff, the second one to
In this section, we show some ways to fine tune the final output of a
piece. We do so using a single measure of a moderately complex piano
piece: a Brahms intermezzo (opus 119, no. 1).
+@cindex Brahms, Johannes
The code for the untuned example shows us some new things.
@lilypondfile[verbatim]{brahms-original.ly}
+
+@cindex dynamics
+@cindex loudness
+@cindex forte
+@cindex crescendo
+@cindex @code{\<}
+@cindex @code{\!}
+
+The crescendo is ended at the half note by the escaped exclamation
+mark @code{\!}.
+
Hairpin dynamics can be indicated using @code{\>} to start a
decrescendo, and @code{\!} to end one. The crescendo is started using
@code{\<} and also ended using @code{\!}. Absolute dynamics can be
-entered using @code{\p}, @code{\mf}, etc.
+entered using @code{\p}, @code{\mf}, etc. All these commands apply to
+the complete chord where they are entered, but for syntactical
+reasons, they must be attached to one of the notes of the chord.
+
+@cindex fingering instructions
-Fingering indications are entered quite simply using @code{-@var{N}},
-where @var{N} is a digit.
+Fingering indications are entered simply using @code{-@var{N}}, where
+@var{N} is a digit.
+
+Now that we have the basic piece of music entered, we want to fine
+tune it, so we get something that resembles the original printed
+edition by Schott/Universal Edition:
@lilypondfile{brahms-tweaked.ly}
-Printed symbols are internally represented by so-called Graphical
-Objects (more colloquially: Grobs). These statements concern the
-grob called `Stem'. Each grob is described by a bunch of settings. These
-setting determine the fonts, offsets, sub-routines to be called on the
-grob, etc. The initial values of these settings are set in the Scheme
-file @file{scm/grob-description.scm}.
+@cindex tuning grob behavior
+
+The basic process that we follow is that we override defaults in the
+printing system. We do this by setting variables in so-called grobs.
+Printed symbols are internally represented by Graphical Objects
+(Grobs). Each grob is described by a bunch of settings. These setting
+determine the fonts, offsets, sub-routines to be called on the grob,
+etc. The initial values of these settings are set in the Scheme file
+@file{scm/grob-description.scm}.
+
+@cindex slur attachments
+
+We start with the slur: the slur in the upper part, running from the F
+sharp to the A, runs from stem to stem in the printed edition, while
+ours starts from the note head at the left. The following property
+setting forces all slurs to run from stem to stem (and not from or to
+note head)
+
+@example
+ \property Voice.Slur \set #'attachment = #'(stem . stem)
+@end example
+
+More precisely, this command extends the definition of the @code{Slur}
+object in the current @code{Voice}. The variable @code{attachment} is
+set to the pair of symbols @code{'(stem . stem)}.
+
+Although this is useful information, it is not very helpful: the
+lilypond backend supports approximately 240 variables like
+@code{attachment}, each with their own meaning and own type
+(eg. number, symbol, list, etc). Besides slur, LilyPond has 80
+different types of Grobs, that may be created in 14 different context
+types besides Voice.
+
+@cindex internal documentation
+@cindex finding grobs
+@cindex grob descriptiosn
+
+The interesting information is how you can figure out which properties
+to tune for your own scores. To discover this, you must have a copy of
+the internals document. This is a set of HTML pages, which should be
+included if you run a binary distribution@footnote{You can also
+compile them by executing @code{make -C Documentation/user/
+out/lilypond-internals.html} in the source package.}. This document is
+also available on the web: go to the lilypond website, click
+``Documentation: other'' on the side bar, click
+``lilypond-internals'', under information for users.
+
+You might want to bookmark either the HTML files on disk, or the one
+on the web. One word of caution is in place here: the internals
+documentation is generated from the definitions that lily uses. For
+that reason, it is strongly tied to the version of LilyPond that you
+use. Before you proceed, please make sure that you are using the
+documentation that corresponds to the LilyPond version that you use.
+
+Suppose that you wanted to tune the behavior of the slur. The first
+step is to get some general info on slurs in lilypond. Turn to the
+index, and look up slur. The section on slurs says
+@quotation
+The grob for this object is @internalsref{Slur}, generally in
+@internalsref{Voice} context.
+@end quotation
+So the grob for this object is called @code{Slur}, and slurs are
+created in the @code{Voice} context. If you are reading this tutorial
+in the HTML version, then you can simply click Slur, otherwise, you
+must look it up the internal documentation: click ``grob overview'' ,
+and select ``slur'' (the list is alphabetical.)
-@separate
+Now you get a list of all the properties that the slur object
+supports, along with their default values. Among the properties we
+find the @code{attachment} property, leading to
+@example
+ \property Voice.Slur \set #'attachment = #'(stem . stem)
+@end example
+
+If you ran the previous example, you have unknowingly already used
+this kind of command. The @file{ly/property-init.ly} contains the
+definition of @code{\stemUp}
+@example
+ stemUp = \property Voice.Stem \set #'direction = #1
+@end example
+
+
+We also want to move around the fingering `3'. In the printed edition
+it is not above the stem, but a little lower, slightly left of the
+stem. From the user manual, we find that the associated grob is called
+@code{Fingering}, but how do we know if we should use @code{Voice} or
+@code{Staff}. In many cases, @code{Voice} is a safe bet, but you can
+also deduce this information from the internals documentation: if you
+visit the documentation of @code{Fingering}, you will notice
@example
- stemDown = \property Voice.Stem \override #'direction = #-1
+Fingering grobs are created by: Fingering_engraver
@end example
-Set a property for all Stem grobs in the current Voice:
-@code{direction} is set to @code{-1}, which encodes down. The setting
-remains in effect until it is reverted.
-@separate
+
+Clicking @code{Fingering_engraver} will show you the documentation of
+the module responsible for interpreting the fingering instructions and
+translating them to a @code{Fingering} grob. Such a module is called
+an @emph{engraver}. The documentation of the @code{Fingering_engraver}
+says,
@example
- \property Voice.Stem \revert #'direction
+Fingering_engraver is part of contexts: Voice and TabVoice
+@end example
+so tuning the settings for Fingering should be done using either
+@example
+ \property Voice.Fingering \set @dots{}
+@end example
+or
+@example
+ \property TabVoice.Fingering \set @dots{}
@end example
-Revert the to the previous setting. The effect of precisely one
-@code{\stemDown} or @code{\stemUp} is neutralized.
+Since the @code{TabVoice} is only used for tab notation, we see that
+the first guess @code{Voice} was indeed correct.
+@cindex setting grob properties
+@cindex @code{extra-offset}
-@cindex dynamics
-@cindex loudness
-@cindex forte
-@code{\f} places a forte symbol under the chord. The forte applies to
-the whole chord, but the syntax requires that commands like forte and
-arpeggio are attached to a note, so here we attach them to the first
-note.
+For shifting the fingering, we use the grob property
+@code{extra-offset}. The following command manually adds an offset to
+the object. We move it a little to the left, and 1.8 staff space
+downwards.
+@example
+ \property Voice.Fingering \set #'extra-offset = #'(-0.3 . -1.8)
+@end example
+The @code{extra-offset} is a low-level feature: it moves around
+objects in the printout; the formatting engine is completely oblivious
+to these offsets.
-On the first chord, a crescendo is started with
-@code{\<}. To be precise, the crescendo start is syntactically attached
-to the preceding note, the @code{d}.
+@cindex reverting grob properties
+@cindex undoing grob properties
-@cindex dynamics
-@cindex crescendo
-@cindex @code{\<}
+We only want to offset a single grob, so after the F-sharp, we must
+undo the setting. The technical term is to revert the grob property.
+@example
+ \property Voice.Fingering \revert #'extra-offset
+@end example
-@cindex @code{\!}
+@cindex property types
+@cindex translator properties
+@cindex grob properties
+@cindex music properties
-The crescendo is ended at the half note by the escaped exclamation
-mark @code{\!}.
+
+There is three different types of variables in LilyPond, something
+which is confusing at first (and for some, it stays like that).
+Variables such as @code{extra-offset} and @code{attachment} are called
+grob properties. They are something different from the translator
+properties, like @code{autoBeaming} and
+@code{automaticMelismata}. Finally, music expressions are internally
+also stored using properties, so-called music properties. You will
+encounter the latter type if you run Scheme functions on music using
+@code{\apply}.
+
+The second fingering instruction should be moved up a little, to avoid
+a collision with the slur. This could be achieved with
+@code{extra-offset}, but in this case, a simpler mechanism also
+works. We insert an empty text between the 5 and the note. The empty
+text pushes the fingering instruction away:
+@example
+ a^" "^#'(finger "5")
+@end example
+
+Lilypond tries to put fingering instructions closer to the notes as
+text instructions. To insert an empty text (@code{^" "}) between the
+finger and the note, we have disguised the fingering instruction as a
+text: @code{(finger "5")}.
+
+Normally, one would specify dynamics in a single voice, and start and
+end dynamics (such as @b{f} and @b{p}) will be aligned with
+hairpins. In this case, we want the decrescendo to be in a different
+place from the piano sign. We achieve this by putting the dynamic
+markings in different voices. The crescendo should be above the upper
+staff. This can be forced by the precooked command
+@example
+ \dynamicsUp
+@end example
+
+However, if you do that, the decrescendo will be too close to the
+upper voice, and collide with the stems. Looking at the manual for
+dynamics, we notice that ``Vertical positioning of these symbols is
+handled by the @internalsref{DynamicLineSpanner} grob.''. If we turn
+to the documentation of @code{DynamicLineSpanner}, we find that the
+@code{DynamicLineSpanner} supports several so-called
+`interfaces'. This grob not only puts dynamic objects next to the
+staff (@code{side-position-interface}), but it also groups dynamic
+objects (@code{axis-group-interface}), is considered a dynamic sign
+itself (@code{dynamic-interface}) and is a grob: it has the
+@code{grob-interface}, with all the variables that come with it.
+
+For the moment, we are interested in the side positioning:
+@quotation
+ side-position-interface
+
+ Position a victim object (this one) next to other objects (the
+ support). In this case, the direction signifies where to put the
+ victim object relative to the support (left or right, up or down?)
+@end quotation
+Between the grob and its support (in this case: the notes in the voice
+going down), there should be more space. This space is controlled by
+@code{padding}, so we increase it.
+@example
+ \property Voice.DynamicLineSpanner \override #'padding = #5.0
+@end example
+
+This command is almost like the command for setting slur attachments,
+but subtly different in its details. Grob properties can be
+manipulated with two commands: @code{\override} extends the grob
+variables with a setting, and @code{\revert} releases this
+setting. This has a certain theoretical appeal: the operations are
+simple and symmetric. For practical use, it can be cumbersome. Both
+commands act like parentheses: you should carefully balance the use of
+@code{\override} and @code{\revert}. The @code{\set} command is more
+friendly: it first does a @code{\revert} followed by @code{\override}.
+
+Finally, Brahms uses music notation is a slightly unorthodox way. Ties
+usually happen only within one voice. In this piece, the composer
+gladly produces ties that jump voices. We deal with this by faking
+these ties: whenever we need such a tie, we insert a notehead in a
+different voice, and blank the stem. This is done in the following
+snippet of code.
+
+@example
+ \property Voice.Stem \set #'transparent = ##t
+ d'
+ \property Voice.Stem \revert #'transparent
+@end example
+
+Finally, the last tie is forced up using @code{\tieUp}.
@node An orchestral score
\property Score.BarNumber \override #'padding = #3
@end example
LilyPond prints bar numbers at the start of each line, but
-unfortunately, they end up a bit too close to the staff in this example.
-A bar number internally is a Grob called @var{BarNumber}. BarNumber
-Grobs can be manipulated through their @var{side-position-interface}. One
-of the properties of a @var{side-position-interface} that can be tweaked
-is the @var{padding}: the amount of extra space that is put between this
-Grob and other Grobs. We set the padding to three staff spaces.
+unfortunately, they end up a bit too close to the staff in this
+example. A bar number internally is a Grob called @var{BarNumber}.
+BarNumber Grobs can be manipulated through their
+@var{side-position-interface}. One of the properties of a
+@var{side-position-interface} that can be tweaked is the
+@var{padding}: the amount of extra space that is put between this Grob
+and other Grobs. We set the padding to three staff spaces.
You can find information on all these kind of properties in LilyPond's
automatically generated documentation in
projects / lilypond.git / blobdiff