Non-numeric time signatures

[Dan Eble]

Simon (and all),

Regarding the request to display 4/2 as cut-c by default, 
https://code.google.com/p/lilypond/issues/detail?id=3286

I think it would make sense to extend the default style to offer a simple way 
to get the doubled symbols:
    2/1 -> double cut-c (Schubert op. 90 no. 3)
    4/2 -> double c (my obscure hymnal)

You mentioned that you would be satisfied if there were a different style for 
your alla breve case.  Do you really need a style or is the following good 
enough?

timeAllaBreve = {
  \once \override Staff.TimeSignature.stencil = 
  #(lambda (grob)
     (grob-interpret-markup grob
      #{ \markup \musicglyph #"timesig.C22" #}))
  \time 2/1
}

Another thing that occurs to me is a possible parallel with non-numeric tempo.  
When the single cut-c symbol is used to indicate 2/1, does it need to be 
annotated with text?  If so, would something like \time “alla breve” 2/1 be any 
better than the way it has to be done now?

Another potential use for that is \time “swing” 4/4.

Regards,
— 
Dan