notelength

[E Appeldoorn]

I'm looking for a way of making a note of indetermined length that looks 
like a breve note.
The note might be 50*4 on the first system, then the system 
automatically breaks. The note then gets tied to the new system where 
the note might be of 101*8 (or any other length). There would be no 
visible barlines along the way..
An example in real life is the nocturne from Serenade Opus 31 by 
Benjamin Britten.