Re: Chord library

[Sébastien Gross]

On Thu, Dec 21, 2006 at 12:45:52PM -0800, address@hidden wrote:
> Here is an example of my "non-programmers" approach to forming a chord
> library: (note this example can only be run in version 2.11.4 or better due
> to a crash issue)

With this solution, fingering and notation will cause a problem.

A basic C Major chord might be strung like:

        C Major
        x     o   o
        +=+=+=+=+=+
        | | | | X |
        +-+-+-+-+-+
        | | X | | |
        +-+-+-+-+-+
        | X | | | |
        +-+-+-+-+-+
          3 2   1

So like: \tag #'M {\relative c { < c\5-3 e\4-2 g\3 c\2-1 e\1> } }

And a D Major can be see as a 2nd fret barre of the C Major:

        D Major
        x
        +-+-+-+-+-+
        XXXXXXXXXXX II
        +-+-+-+-+-+
        | | | | X |
        +-+-+-+-+-+
        | | X | | |
        +-+-+-+-+-+
        | X | | | |
        +-+-+-+-+-+
          4 3 1 2 1

As you can see the fingering changes from a chord to its barre
declinaison.

Then we should define the base (the C form) like:
        \tag #'M_b {\relative c { < c\5-4 e-3 g-1 c-2 e-1> } }

        "_b" would stands for barre

to make it work with the barre form (even if the barre is not shown on
the diagram).
Maybe the Fretboard context could detect if a finger is used on several
strings and then show a barre.

Is it possible to define a fingering like:
 \tag #'M {\relative c { < c\5-3:4 e\4-2:3 g\3-o:1 c\2-1:2 e\1-o:1> } }
Which could be interpreted as:
        - use 3, 2, o, 1, o fingers if there is an open string (o would
          stand for "open string")
        - use 4, 3, 1, 2, 1 fingers if there is no open string
this would factorise previous declarations in one.
But maybe the "-x:y" notation is confusing?

Then we would need to define chords twice.

In an other hand, the ChordNames would name chords as:
"C add8 add10" and "D add8 add10". This is due to the C and E repetition
one octave higer (1st and 2nd string).
For same reason if you string C/E (add the open 6th string) you will
get: "E b6/b10/addb13/add15"
Maybe this is parametable ?

cheers

-- 
Sebastien Gross