LilyPond Beginnershandleiding

Hoofdstuk 4: Tweaking output 95
make up your own – but you will still need some practice. This is provided in the examples
which follow.
Finding the context
But first, what if we had needed to specify the Context? What should it be? We could guess that
slurs are in the Voice context, as they are clearly closely associated with individual lines of music,
but can we be sure? To find out, go back to the top of the IR page describing the Slur, where
it says ‘Slur objects are created by: Slur engraver’. So slurs will be created in whichever context
the Slur_engraver is in. Follow the link to the Slur_engraver page. At the very bottom it tells
us that Slur_engraver is part of seven Voice contexts, including the standard voice context,
Voice, so our guess was correct. And because Voice is one of the lowest level contexts which is
implied unambiguously by the fact that we are entering notes, we can omit it in this location.
Overriding once only
As you can see, all the slurs are thicker in the final example above. But what if we wanted just
the first slur to be thicker? This is achieved with the \once command. Placed immediately before
the \override command it causes it to change only the slur which begins on the immediately
following note. If the immediately following note does not begin a slur the command has no
effect at all – it is not remembered until a slur is encountered, it is simply discarded. So the
command with \once must be repositioned as follows:
{
}
\key es \major
\time 6/8
{
r4 bes8
% Increase thickness of immediately following slur only
\once \override Slur.thickness = #5.0
bes8[( g]) g |
g8[( es]) es d[( f]) as |
as8 g
}
\addlyrics {
The man who | feels love's sweet e -- | mo -- tion
}
8
6
Now only the first slur is made heavier.
sweet
The
love's e
man who feels
motion
The \once command can also be used before the \set command.
Reverting
Finally, what if we wanted just the first two slurs to be heavier? Well, we could use two commands,
each preceded by \once placed immediately before each of the notes where the slurs
begin:
{
\key es \major
\time 6/8