Comment #21 on issue 2717 by [email protected]: Patch: Implement \hidden/\hide as
shorthands for \tweak/\override #'stencil = ##f
http://code.google.com/p/lilypond/issues/detail?id=2717
Regarding comment #20:
\single = "do the following commands and only apply them to the single item
following them, as a \tweak"
\single\once ... is the same as \single ..., and \once\single is nonsense
since \single first converts overrides to a tweak, and you can't apply
\once on a tweak.
"once" and "single" are not synonymous. "once" is the same as "a single
time", but the point is that "\single" applies an override just to a single
item.
Or in other words: \single converts overrides into one or more \tweaks.
This means that you can write something like <\single\hideNotes c e g> and,
in contrast to
\once\hideNotes <c e g>, just the c will get hidden (I can't vouch for what
will happen to the Stem: this will depend on whether LilyPond considers the
NoteHead for c as the cause of the Stem, or rather that of some other note).
I would not care explaining this distinction to Fridolin: he tends to
ignore distinctions such as the distinction between inside and outside of a
fence.
