Comment #8 on issue 2929 by [email protected]: Patch: Allow \tweak to act as a
stand-in for \once\override
http://code.google.com/p/lilypond/issues/detail?id=2929
Second sentence was:
Making tweak optionally accept a grob specification instead of music
to tweak makes it compatible with the behavior of functions such as
\footnote and \shape, and actually serves to simplify their
implementation.
I don't really know how to write this better. You can write something like
\tweak color #red Staff.TimeSignature
or so, and it produces a \once\override Staff.TimeSignature.color #red as
result.
