What’s the best Greek song that Stelios Kazantzidis, Greek singer, has ever made?

Kudos to Achilleas for his comprehensive answer, and for pointing out something unfamiliar to the contemporary Anglosphere: plenty of musical traditions, like Greece, don’t require singers to be songwriters for them to have credibility. In fact, not only songwriters, but  lyricists distinct from songwriters have a high profile—something I find cool, but which went out of fashion in the Anglosphere with Tin Pan Alley.

It took me a long time to warm to Kazantzidis, just as it took me a long time to tolerate Mozart. Both require a different kind of emotional maturity.

My favourite happens to be Η ζωή μου όλη:

My whole life’s a burden:
it takes it all, gives nothing.
My whole life’s a chimney:
I’ve fallen in, I’m burning.

My whole life’s a nonsense,
and my sole possession.
My whole life’s a offering
with no aim or meaning.

My whole life’s a ciggy:
hate it, but still smoke it.
Reaper Man can have it
when it’s time to  scarper.

Actually, that’s not a good translation of the last verse, I just settled on it for the metre. It’s combination of slang, contempt, and fatalism is very Greek, and very arresting…

And yes, the lyricist ended up honour-killing his daughter’s boyfriend. (Άκης Πάνου – Βικιπαίδεια) But the lyric isn’t his, it’s the world’s.

What are the major characteristics of the poetry of Constantine P. Cavafy?

A major characteristic of Cavafy which does *not* come across in the most popular translation (Sherrard & Keeley’s) is the linguistic eclectisism, which adds to the overall feeling of restraint and detachment. Especially when everyone else writing in Greek at the time was idolising the Volkisch ideal of Demotic, his playful alternation of contemporary slang and classicising rhetoric placed him very far from the mainstream; and with the era dominated by the Greek Language Question, language matters a lot in Greek poetry.

Sherrard & Keeley sacrificed that element to make his poetry approachable in English; I think they had to.

Is Spain the only place which has ever been de-islamized? How did they do that?

Crete and Greek Macedonia in 1923, by the Population exchange between Greece and Turkey. Done by expulsions of the kind currently frowned upon (Ethnic cleansing), but which happened quite a bit after both WWI and WWII. On the Greek side, at least, the process appears to have been relatively orderly. Well, as orderly as that kind of thing can be…

EDIT: I forgot: yes, 1923 was orderly; the 1890s in Crete were not, and sectarian violence forced many of the Muslim population to leave by 1900: Cretan Turks. The Muslim population had already fallen from half the island to a third from 1800.

Crete has the distinction of being de-islamised twice. The previous occasion was the Emirate of Crete in the 9th century, which had a reconquista by the Byzantines in 961. Byzantine chroniclers boasted that the entire population was massacred and repopulated from Cappadocia; but of course Nicephoras Phocas was not Reinhard Heydrich, and it’s unlikely that the entire population was converted to Islam to begin with. The remainder of the de-islamisation would have been carried out by Byzantine missionaries.

How widely were German, French and English each used as languages of science in the Europe of the 19th and early 20th centuries?

Greek linguists at the time mostly did German, and some did French. Of the main antagonists, Psichari only wrote in French—but then again, he lived in France. Hatzidakis mostly wrote in German, though he could write in French if he had to.

When I was studying in Greece, I heard distant echoes of a “German school” and “French school” of linguists: you picked your main language and aligned yourself to it. English was used, but not by Greeks; as a language of Greek linguistics it was marginal before WWII—about the same ranking as Italian. (They were distant echoes, because that era had ended by the ’60s. The linguist I heard the echoes from, Δικαίος Βαγιακάκος – Βικιπαίδεια, was born in 1917.)

I have seen instances of Dutch linguists working on Greek (Hesseling) translating their stuff into French to get it read. Sandfeld’s Linguistique Balkanique was ignored until he translated it from Danish to French. So yes, getting your stuff translated was a must if it wasn’t originally in French or German (or, OK, English and Italian). The only language I noted in my reading other than those was Russian, and there wasn’t much of that. (A bit more in Byzantine studies.)