breaking lines in unmetred music

[Jean-marc LEGRAND]

Hi list !

Pfiou : it's been a long time since last time I wrote here. So happy new year 
(and happy next
christmas...).

I have writtte some renaissance song, 4 voices, without any barlines, neither 
time signature.

All is right, except the fact that I only have a long long system that comes 
over the page and
continues out of the paper...

I've tried to put \bar "", but it doesn't work at all.

So does anyone knows how to force "back to the next line" ?

Regards

JMarc