+does not change color. See @ref{Displaying music expressions}, for
+details.
+
+
+@node Using Scheme code instead of \tweak
+@subsection Using Scheme code instead of @code{\tweak}
+
+The main disadvantage of @code{\tweak} is its syntactical
+inflexibility. For example, the following produces a syntax error.
+
+@example
+F = \tweak #'font-size #-3 -\flageolet
+
+\relative c'' @{
+ c4^\F c4_\F
+@}
+@end example
+
+@noindent
+With other words, @code{\tweak} doesn't behave like an articulation
+regarding the syntax; in particular, it can't be attached with
+@code{^} and @code{_}.
+
+Using Scheme, this problem can be circumvented. The route to the
+result is given in @ref{Adding articulation to notes (example)},
+especially how to use @code{\displayMusic} as a helping guide.
+
+@example
+F = #(let ((m (make-music 'ArticulationEvent
+ 'articulation-type "flageolet")))
+ (set! (ly:music-property m 'tweaks)
+ (acons 'font-size -3
+ (ly:music-property m 'tweaks)))
+ m)
+
+\relative c'' @{
+ c4^\F c4_\F
+@}
+@end example
+
+@noindent
+Here, the @code{tweaks} properties of the flageolet object
+@code{m} (created with @code{make-music}) are extracted with
+@code{ly:music-property}, a new key-value pair to change the
+font size is prepended to the property list with the
+@code{acons} Scheme function, and the result is finally
+written back with @code{set!}. The last element of the
+@code{let} block is the return value, @code{m} itself.
+
+
+@node \set versus \override
+@subsection @code{\set} vs. @code{\override}
+
+We have seen two methods of changing properties: @code{\set} and
+@code{\override}. There are actually two different kinds of
+properties.
+
+Contexts can have properties, which are usually named in
+@code{studlyCaps}. They mostly control the translation from
+music to notatino, eg. @code{localKeySignature} (for determining
+whether to print accidentals), @code{measurePosition} (for
+determining when to print a bar line). Context properties can
+change value over time while interpreting a piece of music;
+@code{measurePosition} is an obvious example of
+this. Context properties are modified with @code{\set}.
+
+There is a special type of context property: the element
+description. These properties are named in @code{StudlyCaps}
+(starting with capital letters). They contain the
+@q{default settings} for said graphical object as an
+association list. See @file{scm/@/define@/-grobs@/.scm}
+to see what kind of settings there are. Element descriptions
+may be modified with @code{\override}.
+
+@code{\override} is actually a shorthand;
+
+@example
+\override @var{context}.@var{name} #'@var{property} = #@var{value}
+@end example
+
+@noindent
+is more or less equivalent to
+
+@c leave this long line -gp
+@example
+\set @var{context}.@var{name} #'@var{property} = #(cons (cons '@var{property} @var{value}) <previous value of @var{context})
+@end example
+
+The value of @code{context} (the alist) is used to initalize
+the properties of individual grobs. Grobs also have
+properties, named in Scheme style, with
+@code{dashed-words}. The values of grob properties change
+during the formatting process: formatting basically amounts
+to computing properties using callback functions.
+
+@code{fontSize} is a special property: it is equivalent to
+entering @code{\override ... #'font-size} for all pertinent
+objects. Since this is a common change, the special
+property (modified with @code{\set}) was created.
+