I did get the "coo", and I knew that there was something different with the [u]s (which is my worst vowel because they always sound French), but I had no idea that they were mixed with closed and open [i] (or "ee", "eh"). That's interesting because they also seem to be darker/rounder to my ear. Maybe I am wrong on that.

I wonder why Britten would have set the poem with so many elongated [u]s if they don't exist in the language. Is there a way to know if a word should be pronounced with the French short u or the German U umlaut, other than if it is spelled "ui"?

Graham Johnson gave me full marks on pronunciation/translation, so I would just like to thank you fine folk for that. Thank you!