E vowels tighten up your throat. They're a pain in the ass to sing half the time no matter how strong of a voice you have. Why do you think Sho Bean sings them through her nose?
When Gina Gershon was in Cabaret, she sang the title song like
"Life is a CabUHRAY ole' chum, come to the CabUHRAY" Don't really think it's a big deal, but anyway.
Joel Grey did the same thing in the movie version "Im Cabaret, Au Cabaret, to CabUHRAAAAAY" the little inflection through the nose.
I don't WANT to live in what they call "a certain way." In the first place I'd be no good at it and besides that I don't want to be identified with any one class of people. I want to live every whichway, among all kinds---and know them---and understand them---and love them---THAT's what I want! - Philip Barry (Holiday)