The "notation" documentation on setting automatic beam behavior
<https://lilypond.org/doc/v2.26/Documentation/notation/beams#setting-automatic-beam-behavior>
contains within it this line (end of third paragraph under "Beaming based
on beatBase and beatStructure"):
> New values [of beatBase and beatStructure] given to a particular time
signature are retained and reinstated whenever that time signature is
reestablished.
This line is misleading, if not completely false. For two pieces of proof,
first note this line from further down on the same page:
> When the time signature is changed, default values of Timing.beatBase,
Timing.beatStructure, and Timing.beamExceptions are set. Setting the time
signature will reset the automatic beaming settings for the Timing context
to the default behavior.
Secondly, note this example where switching to another time signature and
back does not "retain and reinstate" the previous beatStructure value:
```
\relative a' {
\time 6/8
% group (4 + 2)
\set Timing.beatStructure = 4,2
\repeat unfold 6 { a8 }
% switch away to any other time signature
\time 3/4
\repeat unfold 6 { a8 }
% does not restore previous behavior
\time 6/8
\repeat unfold 6 { a8 }
}
```
Perhaps it would be worth deleting the erroneous line, or replacing it with
a reference to `\overrideTimeSignatureSettings` which could be used to
change the defaults if desired.
