Fret-diagrams context

[Carl D. Sorensen]

Han-wen,

After trying to get the time to get around to developing a fret-diagrams
context for a couple of years, it's become apparent that I've got too
much other stuff going on to get to it.

I wonder what it might cost to sponsor defelopment of a fret-diagrams
context.  The fret-diagrams context would take a \chordmode sequence and
would produce fret diagrams.  I envision that fret diagrams would be
stored in a hash-table and indexed with a chord (the result of parsing a
chord in chordmode, I expect).

I envision that a lead sheet would look something like this:

   mychords = \chordmode { a d:7 ... }
        
   melody = { a4 b .... }
 
   mylyrics = \lyricsmode {Blah blah blah .... }

   \score {
     <<
          \chords {mychords}
          \fret-diagrams {mychords}
          \relative c' {
           \clef treble
             \key c \major
           \time 4/4
           \melody
         }
         \addlyrics { \mylyrics }
      >>
    }
  
        

I'm willing and able to enter in default fret diagrams for the guitar
(which I expect to be the most likely used).  There also needs to be a
define-fret-diagram that takes a chord and a definition (string for
terse or normal, or alist for verbose), and sticks the definition in the
hash table.

There are two reasons I'd like this functionality.  First, I'd like to
be able to transpose songs with fret diagrams.  Second, I'd like to get
the automatic collision detection properties kicking in when I lay out
the music.  I believe that if the context were enabled, it would allow
both of these actions to take place.

Please let me know what the sponsoring cost would be.

Thanks,

Carl Sorensen