wawa_indication

[David Bobroff]

I'm typesetting a piece which has an indication for gradual 
opening/closing of a wa-wa mute.  I've come up with a solution that I 
think will work for changes that take up enough space but for short ones 
my solution doesn't work.  I've tried to address it like this:


%%%%%%%%
\version "2.11.54"

grad = {
        \override Glissando #'bound-details #'right #'arrow = ##t
        \override Glissando #'arrow-length = #1
        \override Glissando #'arrow-width = #0.25       
}

\relative c' {
        \time 3/8
        \clef "tenor"
        <<
        {
        \grad
        \hideNotes
        g'16*5\glissando c16
        \unHideNotes
        }
        \\
        {
        d,16^\open dis e f fis g^+
        }
        >>
        \time 6/16
        <<
        {
                \grad
                \hideNotes
                a16\glissando g
                \unHideNotes
        }
        \\
        {
                es16[^+\f d^\open c] fis,[\< bes16^\open a]^+\!
        }
        >>
}
%%%%%%%%

In the first measure I'm pleased with the result.  In the second 
measure, the altered glissando graphic does not appear.  I suppose 
there's not enough room for it.  The original manuscript does it with 
hairpins:

http://notendur.centrum.is/~bobroff/lily/wawa.png

I don't think it is necessary to duplicate exactly the original 
notation.  I don't really know how to make a hairpin behave like that. 
Then again, maybe this would actually be more doable than my gliss/arrow 
idea.

Ideas?

-David