Microtonal Helmholtz-Ellis notation in Lilypond: fine-tuning

[Torsten Anders]

Dear Lilyponders,

Finally, I got some microtonal notation working in Lilypond that uses
a special font for the accidentals (i.e. not the usual Feta font),
please see the attached example PDF file. The full Lilypond code is
included at the end of this mail. This example shows a harmonic
seventh chord over C (first as an "arpeggio" and then all notes
together) using the "Extended Helmholtz-Ellis JI Pitch Notation" (HE
for short) by Marc Sabat and Wolfgang von Schweinitz. Besides non-
Feta accidentals, the example also uses accidentals that consist of
multiple signs where additional signs show comma inflections (e.g.,
the septimal comma before the B-flat in the example, the harmonic 7th
over C). The required font and further information about this
notation is available at

   http://music.calarts.edu/~msabat/ms/pdfs/HE-font-2009.zip.

I implemented this microtonal notation by changing the notation of
accidentals to markups, following an idea by Graham Breed. Doing so
did not only allow for selecting a different font, but also for
accidentals that consist of more than a single sign. Changing
accidentals for individual notes in a chord was particularly tricky,
and I used an idea by Mark Polesky for this.

Anyway, although this this approach to microtonal notation is already
usable, it could use some improvements. I would be grateful for
suggestions.

The main problem is the horizontal spacing. Spacing with single-sign
accidentals works fine, Lilypond takes care of that automatically.
However, Lilypond does not know about multiple-sign accidentals, so I
somehow have to create more horizontal space for these manually. The
Lily manual (http://lilypond.org/doc/v2.12/Documentation/user/
lilypond/Horizontal-spacing-overview#Horizontal-spacing-overview)
suggests as a trick to use the following code, however I could not
get this approach working. What am I missing?

  \once \override Score.SeparationItem #'padding = #1

Instead, I globally increased the horizontal spacing (http://
lilypond.org/doc/v2.12/Documentation/user/lilypond/Changing-
horizontal-spacing#Changing-horizontal-spacing).

Any further idea to insert some additional horizonal space before a
note in order to fit in complex accidentals? Spacing of multiple-sign
accidentals in a chord is even more tricky...

The second issue is the readability of the Lilypond code. I defined
the music function \accidental that expects a markup and sets the
accidental of next note to that markup. I also started defining
readable accidental names that are mapped to the respective markup.
For example, the following two notes are first an untransposed C and
then an E a just major third above it: with respect to the
Phythagorean E it is transposed down by a syntonic comma (see the
second note in the attached example).

   c
   \accidental \naturalSyntonicDown
   e

However, I failed to do the same for chord tones. I need to define a
music function that creates the following code, but the markup should
be given as an argument, as above.

\tweak #'before-line-breaking #(accidental-text (markup #:sans "m"))

The problem might be that I do not know how to automatically
translate a Lily-syntax markup (e.g., \markup{\sans "m"}) into the
Scheme-syntax markup required here.

Of course, I also cordially welcome any other ideas for improving
this approach to microtonal notation.

Thank you!

Best
Torsten

--
Torsten Anders
Interdisciplinary Centre for Computer Music Research
University of Plymouth
Office: +44-1752-586219
Private: +44-1752-558917
http://strasheela.sourceforge.net
http://www.torsten-anders.de


-----------------------------------------------
%% Lily code (first various defs and then the score at the end)

\version "2.12.00"

%% Font "HE" must be installed (e.g., on MacOS in /Library/Fonts)
%% Font HE put in as 2nd font: can be accessed as \sans
\paper{
#(define fonts (make-pango-font-tree "Century Schoolbook L"
                                      "HE"
                                      "Bitstream Vera Sans Mono"
                         1))
}

\layout {
   \context
   { \Score
     %% more space between all notes (to allow for extra accidentals)
     \override SpacingSpanner #'base-shortest-duration = #(ly:make- 
moment 1 16)
     %% all accidentals are written as markups
     \override Accidental #'stencil = #ly:text-interface::print
     %% default is natural accidental -- causes error...
     \override Accidental #'text = #(markup #:sans "n")
   }
}

#(define (modify-accidental note-grob prop-alist)
   ;; notehead before-line-breaking callback
   (let ((accidental (ly:grob-object note-grob 'accidental-grob)))
    (if (not (null? accidental))
     (for-each
      (lambda (x)
       (ly:grob-set-property! accidental (car x) (cdr x)))
      prop-alist))))
#(define (accidental-text markup)
   (lambda (grob)
    (modify-accidental grob `((text . ,markup)))))

%% expects a markup and sets accidental of next note to that markup
accidental =
#(define-music-function (parser location markup) (markup?)
   #{
   \once \override Accidental #'text = #$markup
   #})

% %% !! Buggy
% %% expects a markup and sets accidental of next chord note to that
markup
% chordAccidental =
% #(define-music-function (parser location markup) (markup?)
%   #{
%   \tweak #'before-line-breaking #(accidental-text #$markup)
%   #})


%%
%% Selection of accidentals to markups mappings, see HE-font-map.pdf
provided with font
%%
sharp = \markup{\sans "v"}
natural = \markup{\sans "n"}
flat = \markup{\sans "e"}

sharpSyntonicUp = \markup{\sans "w"}
naturalSyntonicUp = \markup{\sans "o"}
flatSyntonicUp = \markup{\sans "f"}
sharpSyntonicDown = \markup{\sans "u"}
naturalSyntonicDown = \markup{\sans "m"}
flatSyntonicDown = \markup{\sans "d"}

%% etc

%%
%% The score
%%

{

   %% there is an accidental for every note
   #(set-accidental-style 'dodecaphonic)

   c'
   \accidental \naturalSyntonicDown
   e'
   g'
   \accidental \markup{\halign #0 \sans "<e"}
   b'

   %% \override does not work for chords nor for accidentals, but
   %% here is a way:
   %% see http://www.mail-archive.com/address@hidden/ 
msg22555.html
   %%
   %% TODO: def function that only expects markup and returns
   %% lambda-expression
   <
     c'!
     \tweak #'before-line-breaking #(accidental-text (markup #:sans  
"m"))
     e'!
     g'!
     \tweak #'before-line-breaking #(accidental-text (markup  
#:halign 0 #:sans "<e"))
     b'!>2

}

Lily-HE-accidentals.pdf
Description: Adobe PDF document

ATT00001.txt
Description: Text document