Setting line-width for individual lines

[Benjamin Bruce]

I know how to set line-width in the \layout block to apply it to the whole 
score. But is it possible to set line-widths on an individual line basis (or 
for groups of lines), for example one width for lines 1-2, and then a different 
width for lines 3-4? I know about ragged-right, but I don't like the look of 
the ragged edge and would rather have the power to specify just how wide I want 
each line to be.

Hopefully that makes sense. Let me know if you have any ideas, or if this is 
too much to ask of LilyPond. Thanks in advance!

Benjamin Bruce