[GLISS] non-timed or non-musical events "z" "y"

[Graham Percival]

I'd like to float two ideas about events.

The first is to define a "null" event which functions like the
empty chord <>.  Although mathematicians and programmers are quite
comfortable with contains with 0 items inside them, this is not a
particularly intuitive concept (just look at the concept of zero
in the history of mathematics!)
This would allow people to write either:
  { c'1\< <>\! }
  { c'1\< z\! }
The non-timed null event z would be inserted after the previous
note (the c'1) is finished.


A vaguely-related idea is to allow easy positioning of musical
events within a note.  Instead of having a non-timed null event
which begins *after* the previous note, we have a timed null event
which begins at the same time as the previous note.  An example
might make that much more clear:
  \new Voice { << { c'1 } { s4\< s s\> s\! } >> }
  \new Voice { c'1 y4\< y y\> y\! }

Of course in complicated piano it would still be necessary to have
explicit voices, but this could simplify such constructs for
string, voice, and wind instruments.


- Graham