Εναρμόνια φθορά στον (Πλάγιο) Πρώτο ήχο / Enharmonic Phrases in (Plagal) First mode

Ποιό πρέπει να είναι το ισοκράτημα; / What should the ison be?

Audio samples

Fr Dositheos Katounakiotis
(doing the score shown below)

Ta Eidola Ton Ethnon [mp3,700 Kb]
Stoma Exousin [mp3, 400 Kb]
Ofthalmous Exousin [mp3,400 Kb]

Stephanos Prousalis
(dong the score below)

Douloi Kyrion (verses) [mp3, 560 Kb]
(however without ison)

Questions/Answers

What is the proper isokratema in the three enharmonic theseis below?

D. Koubaroulis
Some people do ZW ison, some people keep it on PA. I guess both approaches are justified depending on what mode you consider you do in that
passage. If you say you are in Barys Enharmonic From ZW then ZW is justified. If you say you are in First Plagal Pentaphonos then PA is justified.
My personal taste on this is do a low volume PA all the way. Keep it simple. Keep it ison (="straight").

G. K. Michalakis

Most will do Zo enharmonic below the PA which was already the ison. But even "PA = ena to ison" may do the job.

Why is PA' flat in the last example?

G. K. Michalakis
Punctual, special effect that should not be generalized... This makes part of a "spatheion" scale (DI hyphesis, ZW hypesis, PA' hyphesis).

Score

See examples below from Polyeleos "Douloi Kyrion"of Petros Lambadarios in Plagal First Mode.
(click for large)

What is the traditional ison to do in Biolakis' slow Doxology in Plagal First Mode Pentaphonos (so called "enharmonic")?

There are two schools of thought:

a) those that do ZW flat in the enharmonic phrases arguing that it "sounds better" and implicitly considering those phrases to be of Barys Enharmonic mode from low ZW flat.

D. Paikopoulos
[rm] (from cmkon.org)

b) and those that do PA all the way (Karas et al for instance) arguing that the basis of the mode is PA and therefore the ison should be PA. The relative dissonance of PA-ZW flat, they say, gives this mode its special colour.

Prof. Gr. Stathis
Alleluiarion in Plagal First Mode "Pentaphonos"
[doc, 83 Kb]
(offered by S. Gugushvili)

What do they do in the Patriarchate? Mt Athos? Does anyone know?

The following Kalophonic Heirmos is in this mode too:

"Efrikse Ge ..."
by Protopsaltis Panagiotis Halatzoglou, (17th c).,
Plagal First Mode Pentaphonos (so called "Enharmonic")

Th. Stanitsas
[ rm, 2 Mb]
(from ieropsaltis.com)

X. Taliadoros
[rm, ]
(from ieropsaltis.com)