There are some occasions where pieces of First (Diatonic) mode are chanted in Second (Soft Chromatic) mode. Other times, certain passages or melodic phrases of First mode, moving mainly around its basis sound like Second mode. What are those pieces/passages? Why does that happen?

1. The kathisma/prosomoion "Ton Tafon sou Soter" belongs to First mode but is notated as belonging to Second mode and has a "sound" (άκουσμα) of Second mode. See relevant page on the analogion [html].

2. The classical slow Alleluiarion of the Apostolos (by Ioannis Protopsaltis) which is commonly chanted at the Patriarchate is indicated as First mode but is chanted in Second mode for most of its duration (with the placement of a chromatic fthora).

3. The same happens with the idiomelo "En tais Lambrotesi ton Agion Sou" of Great Tuesday (in Holy Week).

4. The beginning of certain papadic compositions of First mode sounds like Second mode. E.g. listen to the beginning of the Koinonikon "Aineite" as chanted by S. Tsolakidis [wma, 346 Kb] .

Are there more examples?

D. Koubaroulis. Assuming PA is the basis of First mode, the two intervals below it are PA 12 NH 8 ZW exactly as in DI 12 GA 8 BOY of Second soft Chromatic. The intervals above PA are PA 10 BOY 8 GA (18 moria) compared to DI 8 KE 14 ZW (22 moria) of Second mode. So, when the melody doesn't show too much GA and stays between the ZW-BOY tetrachord then the intervals are almost identical to Second Soft Chromatic mode. I don't know how to explain "Ton Tafon Sou" and I am not even sure about the above explanation but I haven't come across any better one so far. So I am making this page in the hope that someone will submit a better answer.

The following are my assumptions, not checked for correctness. In some theoretical treatises of the old method of Byzantine chant (like this one Ms Dionysiou [zip] on the analogion) we read the following " if you move up three tones you shall find First mode and this is the Second mode, because the First is one and the same with the Second". If that refers to the base pitches of the notes then it says that the base note of First mode is the same as the base note of the Second mode. In modern terms, if KE is the base note of the First mode (as it is in some old compositions) then KE should be the base note of the Second mode too. That would explain the placement of Second mode on KE by Propsaltis Georgios Raidestinos and it would explain the conversion of First to Second on the same note in "Ton Tafon sou" and the other pieces mentioned above. Just a thought.