@funindex \tag
@funindex \keepWithTag
@funindex \removeWithTag
-@funindex \pushToTag
-@funindex \appendToTag
@cindex tag
@cindex keep tagged music
@cindex remove tagged music
-@cindex splice into tagged music
The @code{\tag #'@var{partA}} command marks a music expression
with the name @var{partA}.
@end multitable
The arguments of the @code{\tag}, @code{\keepWithTag} and
-@code{\removeWithTag} commands should be a symbol
-(such as @code{#'score} or @code{#'part}), followed
-by a music expression.
+@code{\removeWithTag} commands should be a symbol or list of
+symbols (such as @code{#'score} or @code{#'(violinI violinII}),
+followed by a music expression.
In the following example, we see two versions of a piece of music,
one showing trills with the usual notation, and one with trills
command with a list of multiple tags: this will only remove tagged
sections not given in @emph{any} of the tags.
+@cindex tag groups
+@funindex \tagGroup
+While @code{\keepWithTag} is convenient when dealing with
+@emph{one} set of alternatives, the removal of music tagged with
+@emph{unrelated} tags is problematic when using tags for more than
+one purpose. For that reason, @q{tag groups} of related tags can
+be declared:
+
+@example
+\tagGroup #'(violinI violinII viola cello)
+@end example
+
+declares the respective tags as belonging to one tag group.
+
+@example
+\keepWithTag #'violinI @dots{}
+@end example
+
+will then only be concerned with tags from @code{violinI}'s tag
+group: any element of the included music that is tagged with one
+or more of tags from this set but @emph{not} with @code{violinI}
+will get removed.
+
+To any @code{\keepWithTag} command, only tags from the tag groups
+of the tags given in the command are visible.
+
+Tags cannot be members of more than one tag group.
+
+@funindex \pushToTag
+@funindex \appendToTag
+@cindex splice into tagged music
+
Sometimes you want to splice some music at a particular place in an
existing music expression. You can use @code{\pushToTag} and
@code{\appendToTag} for adding material at the front or end of the
@end lilypond
Both commands get a tag, the material to splice in at every occurence of
-the tag, and the tagged expression. The commands make sure to
-copy everything that they change so that the original @code{\test}
-retains its meaning.
+the tag, and the tagged expression.
@seealso
Learning Manual: