I mean, other than the added "Hs," those aren't modified vowels. "Way" and "Day" both have e-i diphthongs (using IPA symbols). One could argue she was placing undue stress on the second half of those diphthongs, but they're certainly not modified vowels.
"The other thing is that composers are rarely stupid when it comes to writing in high notes. Very often the belting moment will come on an easily understood vowel or a word that's been repeated several times."
That depends on the composer, and there are lots of examples that show little to no composer thought about vowels in relation to tessitura, several of which have been mentioned in this thread.
Updated On: 8/2/12 at 08:38 PM