Byzantine chant and microtones

[Erich Enke]

Hi all,

I just happened across a Sept 2010 post on lilypond-devel regarding
microtones.  It reminded me how I've been wanting to work on Byzantine
notation support for lilypond.  I would love to have a tool that could
actually transcribe between western and Byzantine notation, and
produce midis.  That would be amazing.

The choice of lilypond is clear.  It's open source.  It would allow,
ultimately, for musical searching of a music database, and various
other musico-analytical researches and scripting.  It's free.  There's
internationalization.

So, toward that end, I can describe the needs of Byzantine notation.
What I'm hoping for are some tips and pointers of where to get
started, some basic understandings of the underlying pitching system,
and a general idea of the sort of work and difficulties I might come
across.

In Byzantine church music (not sure on other forms of Byzantine
music), we have the following:

1) A notation that is completely relative, based on a particular place
in a scale (roughly analogous to saying "Start on fa").  There is no
notion of absolute pitch whatsoever.  Just interval.  This allows for
easy accommodation of the same music to different chanters' voices
without transposition.  Likewise, there is no necessity for a key
signature.  Only scale.

2) A one-to-many correlation between Byzantine neumes and Western
notational elements.  One Byzantine neume might translate into several
Western noteheads, dynamic markings, and stylistic markings
simultaneously.

3) An entirely different font, with generally, but not strictly
left-to-right (but with Arabic, right-to-left) direction.  Sometimes
neumes are stacked, and sometimes seems more like adding linguistic
diacritical markings.

4) A multitude of standard (within Byzantine chant) scales, which have
microtonal intervals.  Many Byzantine music theoreticians break down
an octave into 72 "moria".  6 moria are a Western half step.  But
different theoreticians differ on the exact spacing.  Here's one
version (using our version of solfege: Ni, Pa, Vu, Ga, Di, Ke, Zo,
Ni):

Soft Chromatic: Ni - 8 - Pa - 14 - Vu - 8 - Ga - 12 - Di - 8 - Ke - 14
- Zo - 8 - Ni'
Hard Chromatic:          Pa - 6 - Vu - 20 - Ga - 4 - Di - 12 - Ke - 6
- Zo - 20 - Ni' - 4 - Pa'
Diatonic:          Ga - 12 - Di - 10 - Ke - 8 - Zo - 12 - Ni - 12 - Pa
- 10 - Vu - 8 - Ga'
Enharmonic:    Ga - 12 - Di - 12 - Ke - 6 - Zo - 12 - Ni - 12 - Pa -
12 - Vu - 6 - Ga'

The Byzantine enharmonic scale is the only one that fits on the piano
nicely, corresponding to the Western diatonic scale.

5) To make matters more tricksy, Byzantine music isn't even
octave-based.  So, when you extend beyond these ranges, there are
standard expected intervals, but they're predictable on a
tetrachordal, trichordal, or pentachordal basis, not on octaves.

6) There's a syntactic rules of orthography that could ideally be
included, including which way to properly notate something in relation
to the particular accentuation of your text.

7) The fundamental assumption of the music fitting to the text, and
not vice versa.  It is primarily the words that are read and properly
spaced, and the neumes are read in the periphery.

There's probably other points I'm missing, but those are some of the
main ones.  I expect that this challenges core musical assumptions
lilypond may hold.  If lilypond is to be truly a music engine of the
world, and not just of and for Western culture, then this interaction
and growth will be beneficial, though some core refactoring would
probably be necessary (I'm guessing).

Anyway, I hope you found that brief survey to be interesting, at
least, and I look forward to what advice you might have to offer.

Erich