Part 9: Serperoth explains some ancient Greek annunciation.
So I went and did this recording I promised, after being riddled with a bad case of hiccups all afternoon.This is how they are pronounced in Modern Greek. The υ is pronounced as i (like in fish, for example), not as u nowadays, but in Ancient Greek it was apparently closer to a u sound, as Sleep of Bronze did in his own recording, although opinions do differ (and I personally was never informed of that until googling it now).
So, Ancient Greek had a bunch of vowels that all did very very similar things. These are all the Greek vowels, and vowel diphthongs:
α, ι, η, υ, ε, ο, ω and αι, οι, ει, υι, ου. In order, they are pronounced as follows: a, i, i, i, e (as in energy), o (fog), o, e, i, i, ee (kinda like reed), u (Utrecht).
As you can see, we have about 5 ways to write very similar sounds. Vowels are further separated into three categories. Long, short, and 'mixed' (a more direct translation would be bitemporal, but that sounds kind of odd), which were either short or long according to the word, what came before/after, etc.
Long: η, ω
Short: ε, ο
Mixed: ι, υ, α
This did matter to intonation and tonal marks (mentioned just a bit lower).
In Ancient Greek, vowels could also carry a tonal mark, or a spirit (or both). These marks go on top of the letter (think of the dot on i and j, or umlauts in German) if it's lowercase, and in the top left side if it's a capital.
Spirits are the easy ones, and there's only two of them ψιλή ( ᾿ ), and δασεία ( ῾ ). On my screen the difference is miniscule, and I cannot fix it, but basically the ψιλή has the curve to the right, the δασεία to the left. Their rule is pretty simple: Every vowel that is at the beginning of the word, or the second vowel of a vowel diphthong gets one. Also ρ (pronounced like r) always gets a δασεία. That's pretty much it, they matter more when conjugating verbs in various tenses, other than that they change the pronunciation a bit.
Tonal marks, there's three of them: βαρεία ( ` ), οξεία ( ʹ ), and περεισπωμένη ( ~ ). Their rules are a bit less ultra-simple than spirits.
The big one is that all short vowels get the οξεία, including mixed ones which are short in that particular word. Long vowels in syllables before long vowels also get the οξεία. The best rule I've found regarding the βαρεία is that it replaces the οξεία in the final syllable of a word. So for example the article τό (neutral article) would get one but τὸκος wouldn't. The most commonly-used rule regarding the περεισπωμένη is that it goes on a long vowel in a syllable before a short vowel. There are many more rules regarding which tonal marks become other tonal marks (including vowels changing as verbal forms change), but those are a baseline without going into the clusterfuck that is conjugation.
I would like to mention that the above is all based on a 'translation' of Ancient Greek, to make writing and reading it more understandable for later audiences, considering how (for example) Ancient Greek had no lower case letters. Also, the marks mentioned above were still used until 1982, when it was replaced by the monotonal system (no spirits, only οξεία), and a lot of the information here is from a site about restoring the polytonal system, as well as what I remember from school at the ages of 12-16/17 or so.