Request for Comment - Chordname strategy

[Han-Wen Nienhuys]

address@hidden writes:
> After having mostly completed a rewrite of the ChordName to pitch code, it
> became apparent to me that the opposite problem (converting a chord
> representation to pitches) is much easier. Perhaps a regrouping might be in
> order.
>
> [..]
>
> Implementation of chord representations would be much easier if we
> were to consider chord names within a .ly file to be a typsetting
> language for chords than if we were to consider them to be (as they
> currently are) a convenient way to specify pitches in a chord.

Very sharp observation!

I'm not all that much into the chord code, but this seems like a smart
move -- this is essentially how the figured bass support works right
now: <1 3 6+> is just a list of numbers, which are printed, and MIDI
is possible (left to the user as an excercise, patches appreciated :-)

Some loose thoughts from  the top of my head:

  * Will this invalidate your other (unpublished) patch? Should the
    other one go into 1.6 (my engineering guts say no, but otoh,
    chords in 1.6 are broken anyway, so any improvement is good)

  * We're sort-of ducking the problem if we don't provide chords ->
    midi output. But that should be feasible, right?

  * How much hope is there for automated conversion from old style
    chord input?  
 
  * If you're going to support "Free Improv", it's practically as
    powerful as lyrics. Perhaps the easiest way to pull this is off is
    to write a music transformation function (a la \apply), that takes
    a bunch of lyrics and changes that into markup or (for MIDI)
    notes. (some \newchords support should be added though, since
    interval numbers will confuse the normal \lyrics mode).

  * How much hope is there for styles? One of the ideas of the current
    chord code is that you can change the style from normal to jazz or
    american (?) by setting a single property -- this would be
    attractive for people that prefer reading a specific style of
    chords. (I'm not sure how much this is a real problem, though)

-- 

Han-Wen Nienhuys   |   address@hidden   |   http://www.cs.uu.nl/~hanwen