Re: remove a staff

[Simon Albrecht]

On 09.10.19 13:14, MING TSANG wrote:
> Thank you for the answer. I am able to hide every thing except the key 
> signature and bar number.  I can live of bar number but want the key 
> signature hided.


Again: a qualified answer would require you giving an actual _code_ 
example, else it’s impossible to tell what you are doing that leads to 
the image. I already sent a link to the instructions on tiny examples, 
which are _very_ important.

But two hints already:

If you don’t want a staff to be printed, why do you even have a staff in 
the first place? Both Lyrics and FiguredBass work perfectly well without 
a staff.

If you want to hide (or omit) something but don’t know the grob name or 
which context it lives in, the Internal Reference (IR) is your friend. 
The Learning Manual already explains how to use it in such a case: You 
want to look at the index of grobs in section 3.1 of this manual 
<http://lilypond.org/doc/v2.19/Documentation/internals/index.html>. Find 
the grob you want to override (both \hide and \omit are internally 
overrides). Now you have the grob name.
If the grob happens to live in Voice (or other bottom contexts), you 
don’t need to specify the context. Otherwise you need to find out in 
which context it does live. Follow the link to its page, at the top of 
that page follow the link to the Engraver that creates the grob, e.g. 
<http://lilypond.org/doc/v2.19/Documentation/internals/bar_005fnumber_005fengraver>. 
Now at the _bottom_ of that page you can read: “Bar_number_engraver is 
part of the following context(s): Score.” So you need

\omit Score.BarLine

HTH, Simon