Re: Modifying Chordnames ­ bug or feature?

[Carl Sorensen]

On 7/16/11 4:20 PM, "harm6" <address@hidden> wrote:

> 
> 
> Hi,
> 
> trying to modify chordnames (version 2.14.1) I'm running in a strange
> behaviour.
> 
> 1. Compiling http://lsr.dsi.unimi.it/LSR/Item?id=750 gives:
> 
> ERROR: Wrong number of arguments to #<procedure my-chord-name->pop-markup
> (pitch)>
> 
> 
> 2. So I tried my own definition.
> Copying, modifying and simplifying code from chord-name.scm, I came up with
> 
> %begin
> ---------------------------------------------------------------------------
> 
> #(define (myChordNames  pitch lowercase?)
> 
>    (define (pitch-alteration-semitones pitch)
>      (inexact->exact (round (* (ly:pitch-alteration pitch) 2))))
>     
>    (define (conditional-kern-before markup bool amount)
>      (if bool
>          (make-line-markup
>           (list (make-hspace-markup amount)
>           markup))
>          markup))
>      
>    (define (accidental->markup alteration)
>      (if (= alteration 0)
>          (make-line-markup (list empty-markup))
>          (conditional-kern-before
>           (alteration->text-accidental-markup alteration)
>           (= alteration FLAT) 0.2)))
>     
>    (let* ((name (ly:pitch-notename pitch))
>           (alt-semitones  (pitch-alteration-semitones pitch))
>           (n-a (cons name alt-semitones)))
>      (make-line-markup
>       (list
>        (make-simple-markup
>          (vector-ref #("C" "D" "E" "F" "G" "A" "B") (car n-a)))
>        (make-fontsize-markup -3
>         (make-raise-markup 1.5
>          (accidental->markup (/ (cdr n-a) 2))))))))
>         
> myChords = {
>   \set chordRootNamer = #myChordNames
> }
> 
> %--------------------------- Test ----------------------------------
> 
> \chords { \myChords cis ces }
> 
> %end
> ------------------------------------------------------------------------------
> ----
> 
>         It works as expected.
> 
> 3. But trying to delete "lowercase?" in the first line of
> myChordNames-Definition gives the some ERROR as above!?
> 
> And it is possible to replace "lowercase?" with any other expression and it
> will work!!
>                
>                 #(define (myChordNames  pitch bla-blub) ...  works!
> 
> 4.So I tried the LSR-Snippet again, adding bla-blub:
> 
>                 #(define (my-chord-name->pop-markup pitch bla-blub) ...
> 
>                 and ... it works !!!
> 
> 
> Is this a feature for something or a bug or what's going on here??


The syntax of the chord root namer has changed between 2.12 and 2.14.  The
chord root namer now needs both a pitch and a boolean value that says
whether minor chord names should be lowercase.  So LilyPond will always pass
a pitch and a boolean to the chord root namer.

The LSR snippet uses the old syntax -- chord root namer only takes a pitch.

To make the snippet work (and ignore the possibility of making minor chords
lowercase), just add an extra argument to the definition of myChordNames
(just like you did with bla-blub).  It will then work -- your myChordNames
procedure ignores the boolean value passed it by LilyPond, which is just
fine.

HTH,

Carl