Ahem, I said it was a transliteration of the Russian spelling, not of the pronunciation. The idea is that one can easily reconstruct the Cyrillic from my Romanized version--I haven't yet developed a Qwerty-like Cyrillic layout for my Mac. A phonetic transcription would be rather different throughout. And if you want to get picky, most Russians would sing "yihsho", "ihsho" or "eesho" rather than "yesho", not to mention that the palatalization is different for "sh" than for "shch".

Russian pronunciation follows fairly directly from spelling, so if you know the basics and word stresses, phonetic cribs are unnecessary. If you don't, you're surely going to butcher the palatalization, if nothing else--I get a nails-on-a-blackboard sensation just thinking about the from-phonetics singers I've heard.