Re: Help for \beamExceptions

[Richard Shann]

On Fri, 2015-09-04 at 20:20 +0200, David Kastrup wrote:
> Richard Shann <address@hidden> writes:
> 
> > On Fri, 2015-09-04 at 19:25 +0200, David Kastrup wrote:
> >> Richard Shann <address@hidden> writes:
> >> 
> >> > On Fri, 2015-09-04 at 18:56 +0200, David Kastrup wrote:
> >> >> Richard Shann <address@hidden> writes:
> >> >> 
> >> >> > I seem to have run into a snag with re-writing
> >> >> > default-time-signature-settings, it works ok if there was previously a
> >> >> > rule for a time signature, but adding a rule for one (such as 6/8) 
> >> >> > which
> >> >> > has none doesn't result in the beaming pattern being used. Here is a
> >> >> > minimal example. The first bar shows the pattern desired, and this is
> >> >> > put into the value for 'beamExceptions in the 6/8 alist, but the 
> >> >> > second
> >> >> > bar is not then beamed to follow that pattern.
> >> >> 
> >> >> That's likely because 6/8 triggers a special case relying on the context
> >> >> property
> >> >> 
> >> >>      (beamHalfMeasure ,boolean? "Whether to allow a beam to begin
> >> >> halfway through the measure in triple time, which could look like 6/8.")
> >> >
> >> > It sounds like I am tackling this at too low a level then. Is there a
> >> > more user-accessible way of setting the beaming rules for an entire
> >> > score containing many movements with a variety of time signatures?
> >> 
> >> Just unset the darn property if you don't want its effect.
> >
> > which property do you refer to?
> 
> beamHalfMeasure.  What other property were we talking about right now?
> 
> >> At any rate, I don't understand why you are not using
> >> \overrideTimeSignatureSettings to begin with rather than meddling
> >> with the alists used internally.
> >
> > Is that to say that my explanation before "it applies
> > to a particular instance of a time signature change, the user has to
> > re-define (or cut and paste) to use it in another part of the score."
> > was unclear?
> 
> It's wrong.
> 
> > As far as I can see, \overrideTimeSignatureSettings needs to be
> > invoked at every time signature, rather than being applied to a
> > complete book.
> 
> How did you reach that conclusion?  Have you _read_ the documentation of
> \overrideTimeSignatureSettings I pointed you to?  Where does it say
> anything like that?
> 
> > Please correct me if I am wrong, but at the moment I don't know how a
> > user can place a something at the top of a LilyPond file that will
> > result in a particular beaming rule being applied whenever they use a
> > particular time signature.
> 
> \layout {
>    \overrideTimeSignatureSettings ...
> }
> 

Thank you, that was the bit that is missing from the page you referred
to. I suggest that this text from that page:

Alternatively, the default values of all these time-signature-based
variables, including baseMoment and beamExceptions, can be set together.
The values can be set independently for several different time
signatures. The new values take effect when a subsequent \time command
with the same value of the time signature is executed: 


should become

Alternatively, the default values of all these time-signature-based
variables, including baseMoment and beamExceptions, can be set together.
The values can be set independently for several different time
signatures. This can be done in a \layout {} block when it affects all
the passages with the specified time signature in the score block it is
placed in (or all the score blocks if the layout block is at the top
level). Or if placed in the music, the new values take effect when a
subsequent \time command with the same value of the time signature is
executed and affects only the staff in which it is placed: 

with, perhaps an example of the 

 \layout{ \overrideTimeSignatureSettings ... }

use, which I would have thought is mostly what people want (consistent
beaming for a given time signature throughout a work).

Richard