Re: Graphic background behind systems

[Paul Booker]

> The markup part takes nearly no space at all and is placed behind the score: 
> <http://lilypond.1069038.n5.nabble.com/file/n187856/Zwischenablage01.gif> 
> But I'm working with LP 2.19.30 and 2.19.25. 
> Maybe something has changed since those versions?
> 
Hi Klaus,

I don't really want to go back to an earlier version, so I've been browsing
the LSR and found something which might work in a similar way, though
different to my original plan.

\version "2.11.56"
\relative c'' {
         a1 a  a
         -\tweak #'extra-offset #'(-2.5 . -15)  % move to right position
         -\tweak #'layer #-1  % place in bottom layer
         ^\markup {
         \with-color #(rgb-color 1 0.5 0.5) % specify color
         \filled-box #'(0 . 1) #'(0 . 25) #0  % specify size
         }
         a
}
from 

http://lists.gnu.org/archive/html/lilypond-user/2008-09/msg00083.html

I should be able to move forward with this, though I can't find an
explanation of the tweak prefixes.
Do you know the difference between
-\tweak
^\tweak and 
 \tweak 

in the above script? It doesn't work without them!
Cheers
Paul