Two questions

[ghe]

Hi list,

I have two questions, to which I did not find an answer in the manuals; I 
apologize in advance if they are answered there.

(1) I try to typeset choir music, on two staffs, without bars.  Most 
sentences are separated by breathes (one above each staff), but sometimes 
an explicit *span* bar needs to be included.  In short, commas in the text 
become breathes, and full stops become span bars.  How can I do this?  I 
tried:

\context { \Staff \remove Bar_engraver }

but then the clefs disappeared on all lines except the first one.  So I 
tried

\context { \Staff \override BarLine #'transparent = ##t }

and

\context { \Staff \override BarLine #'stencil = ##f }

but in both cases it seems that the bars are still there, albeit invisible 
(which means that some space is wasted and that the output does not look 
optimal).  Moreover, it seems that it is then not possible to put explicit 
span bars when I actually need them, or to print the final bars.

(2) The second question is related to the first one: if an explicit bar is 
put somewhere and if LilyPond determines that it should not be there 
(because it is not aligned with the rythm), it prints a "warning: barcheck 
failed at:" message.  Is it possible to circumvent the problem, or to 
disable these warnings?

Thanks in advance,

--ghe