Re: fisisis impossible?

[Noeck]

Hi Bart,

fisisis is not part of the input language (of any defined input
language). So from this technical point, it can't work.

I wanted to write that there is no symbol for it. But then I found this:
http://dictionary.onmusic.org/terms/3687-triple_sharp

> Etude no. 10 from Douze etudes dans tous les tons mineur, Op. 39 (1857), by 
> Charles-Valentin Alkan.

You can make a fisis look like a fisisis by this override (which can
surely be made more elegant or turned into a tweak):

\version "2.19.80"

isisis = {
  \once \override Accidental.stencil = #ly:text-interface::print
  \once \override Accidental.text = \markup {
    \concat {
      \musicglyph #"accidentals.sharp"
      \musicglyph #"accidentals.doublesharp"
    }
  }
}
\relative {
  \isisis fisis'
}

It's not impossible that these triple-accidentals could be added to both
the input language and the music font. However, I am not convinced that
it should be used :)

Best,
Joram