I think that, in order to understand the passage of Chrysanthos concerning the 'rhythm' of Iakovos' singing, we must have in mind the original (or another, old) meaning of the word 'rhythm', i.e. 'shape'. In this sense we can also speak about 'rhythm' in the visual arts. So, Iakovos was destroying the 'shape' of the automelon, so that its prosomoion has a full (entelh) cadence at the end of a period of the words, a medial cadence at the place of a comma of the words of the prosomoion, in others words to make the syntactic structure of the prosomoion conform with its music. But because the syntactic structure of the prosomoion does not always coincide with the syntactic structure of the automelon, Iakovos tried to alter the music of the Automelon when adapting the words of the prosomoion (retaining of course some similarity to the music of the Automelon), so the music of the prosomoion reflects faithfully its syntactic structure. So, he was singing with (Chrysanthos' expression) 'melopoiia kata ta nooumena', i.e. setting to music according to the meaning. This is exactly reflected in the whole Iakovos' work: e.g. in his Doxologies. The older Doxologies by Balasios, Bereketis, Germanos and, to a lower degree those by Daniel and Petros Lampadarios, follow basically the same pattern in every one of their verses. Although the verses of a doxology are not prosomoia, their singing, as well as the singing of the old or older polyeleoi, followed the custom found in the ancient psalmody (see e.g. the rubrics in Asmatic offices; very often only the music of the first verse is given in the Mss and the rest are sung 'according to this'), i.e. a certain pattern to be followed (the same custom holds also for western psalmody). But Iakovos Doxologies deviate strongly from this rule; they are composed according the meaning, using new high or low points, phthorai and other devices of 'word painting'. In other words, they are not so much 'strophic'; they are 'through composed'. The same manner of composition has strongly affected his Doxastarion: in a frame of old sticheraric, traditional, long 'theseis', new compositional devices are present, e.g. a) new (frequent) use of phthorai but through old formulas b) short sticheraric formulas (coinciding to the ones by Petros) etc. So, Iakovos is at the same time traditional and innovative. He wanted to protect the long old sticherarion (= his conservatism) from disappearance (it was thought already as too long, so Iakovos composed only a Doxastarion and not a full stichararion), but he thought he had to shorten and to 'modernize' it (through devices like the above mentioned), so that at least something of it be preserved; this was maybe the only way to for the old sticherarion to survive.