+@funindex \single
+@cindex tweak, generated from override
+Now for @emph{overriding} the transparency of a graphical object,
+we could have used the shorthand @code{\hide} as explained above.
+Tweaking is a different operation, affecting only properties
+generated from a single music expression. It turns out that we
+can convert overrides into tweaks using @code{\single}, making it
+possible to rewrite the above example as
+
+@lilypond[quote,fragment,relative=2,verbatim]
+<<
+ {
+ \single \hide Stem
+ \single \hide Flag
+ \tweak Stem.length #8
+ b8~ b\noBeam
+ }
+\\
+ { b8[ g] }
+>>
+@end lilypond
+
+In this particular case, the difference to @code{\once \hide} is
+not apparent. It is important when there are several objects at
+the same point in musical time (like noteheads in a chord). In
+that case, @code{\once} will affect all of those objects while
+@code{\single} will only affect a single one, the one generated by
+the immediately following music expression.
+
+@node Simulating a fermata in MIDI
+@unnumberedsubsubsec Simulating a fermata in MIDI