This workshop was held in a Novus Ordo parish school classroom and the
president of Una Voce LA was there, lurking in the doorways.  

Mr. Harburg did a pretty fair job.  I was under the impression that he would
be giving a presentation from a series that he has been doing, but after all
is said and done it seems this may well have been his first foray into the
limelight of public attention for this work.  He has a very traditional sense
about him, and has an obvious desire to learn and develop his skills.  He
is a good singer, a bass, and projects an air of passion and enthusiasm
for Gregorian Chant, the Classical Notation thereof, and its proper use
by either all men or all women in the liturgical setting, but not mixed men
and women in the main.  This was most interesting for me to hear about.

He proposed the use of the Ison (pronounced EE-sohn), as antiphonal
exchange from verse to verse.  This means that the men, for example,
may begin a chant and sing the first verse, while the women sing the Ison
for that chant.  The identity of the Ison is determined by the MODE of the
chant.  We did not get into what the mode is in all it's aspects, but it is
clearly not comparable to a key signature or a tempo marking or such
things in Western music.   I would like to know more about this topic.  

He provided a chart among his handouts which has the following items for
each of the 8 modes:

Mode   Ison    Final   Domin     Range    Greek Name      Mood          Steps
I        Re/Do    Re       La         Re-La          Dorian           Gravis        T-s-T-T
II       La/Re      Re       Fa         La-Fa       Hypodorian       Tristis        T-s-T-T-s
III        Mi         Mi        Ti          Mi-Ti        Phrygian        Mysticus      s-T-T-T
IV        La         Mi       La          Ti-Fa    Hypophrigian   Harmonicus     s-T-T-s
V          Fa         Fa        Do        Fa-Do        Lydian           Laetus        T-T-T-s
VI         Fa         Fa        La        Do-La     Hypolydian       Devotus     (s)-T-T-s-T
VII      Fa/Sol     Sol      Re       Sol-Re     Mixolydian        Angelicus    (T)-T-T-s-T
VIII    Sol/Do   Sol       Do      Sol-Do   Hypomixolydian  Perfectus      T-T-s-T


We did not have time to explore all these things, but Aaron used the Mode I, II
and VI as examples for us, by playing a recording off of a G4 connection (I was
amused that he did not come prepared with a more reliable cassette tape or
even a CD player for this - but everyone's doing the techy thing these days!),
in which two groups sing this way, one singing long "O" (like in snow or doe)
on the Ison pitch (indicated above), while the the other group sings one verse
of the chant.  

In the Mode I example, the men began singing the continuous Ison as a
background, while the women sang the chant.  It was Kyrie from Missa Orbis
Factor, Mass XI.  I don't recall what key we sang in but if it were in C, the
men were singing a D (Re) while the women sang the first Kyrie eleison.  
When the women had sung the first Kyrie, then they switched
to the Ison (octave above where the men had been, on D), while the men
sang the second Kyrie, etc.  Alternating this way, men and
women do not have to sing an octave apart from each other, which always
renders Chant compromised!  

Aaron said that either Re or Do could be sung for the Ison (as the chart
shows, "Re/Do"), depending on which sounds better for the selection at
hand.  For this piece, since the final note of each phrase is a D, the choice
of D (instead of C) sounds better.  I was amused to see that a droning
C, which is a major second interval below the D, somehow does not sound
too dissonant when used as the Ison.  But the D as Ison does sound more
appropriate.  There is also the option of moving your Ison from C to D
and perhaps even back again, within the same Kyrie.  I'm not sure where
this move would take place though.  Aaron said that this Chant tradition
is very common in the Eastern Church, and the Orthodox, and they even
use an interval of a perfect Fifth for the Ison in many pieces.  I do recall
hearing that, but I have never sung it.

We did two more examples, the second of which was the Sanctus from
Missa de Angelis, mode VI.  The Ison would be Fa, as in the chart above,
and therefore, if this Sanctus is sung in the key of C, the Ison is an F.
That's the note that the first word, Sanctus, begins and ends on.  The Ison
is sung as "O" all the while the chant is sung IN UNISON, that is, with
everyone singing the SAME NOTES, not an octave apart.  Generally, the
parts switch at the double bars, which were called "Major Break."  But this
Sanctus has no major breaks, only single bars.  Therefore, the choir can
switch at the single bars.  In the end, the choice of what to do in this
regard is determined by what sounds appropriate. The Chant has a way
of letting you know what it wants you to sing.  It is important to be able
to allow the chant to teach you how to make it beautiful. This is a very
mysterious process.