Emily F. listening assignment #3 vowels

Emily F. listening assignment # 3 vowels: 
Anna Netrebko: Her mouth was way open on every vowel, high and low in the range. I feel like it was more than necessary and wondered if it was because she felt like she needed more volume. I got the feeling of a bunched tongue, and an [ng] quality to the opening of her mouth, and her sound. Her lips were quite rounded most of the time, and I liked that the corners were tucked in even on the [i] vowels, but the "alligator" openness with the (possibly) bunchy tongue made everything kind of the same (tone quality and vowel) and a little swallowed. I also enjoyed watching Martin Scorsese's blinking. :)
Simon Keenlyside: I really enjoyed this whole performance. His lips were quite rounded on all [o] [u] and [i] vowels. There was more spreading of the lips on [e] and [a] but I would say that he never had really spread lips, the corners were always tucked in, even on the brightest [e]s. The rounding was even more pronounced on the [i] vowel when the pitch was high, my guess is because if it were more open or bright that it would be too piercing (formant thing, probably?). I felt like he had great molar space on everything. And the performance seemed effortless, despite the great amount of activity going on. His lips were very active, along with the rest of his face and body, but it wasn't strained or tense, just energetic.
Jonas Kaufmann: The overall effect I saw in his mouth opening was a downward pull with the corners of the lips. I wanted to see more "smile" in the cheeks. There was less overall activity in the lips than Keenlyside's, but more activity as the song progressed. The [e] vowels were particularly pulled down in the beginning. The mouth opening seemed appropriate for the volumes and pitches (wider open for higher/louder notes and less open for softer/lower notes), but occasionally in the quieter sections it seemed that more molar space could have been used.   When there was more intensity in the music, the lip rounding and channelling was more obvious.
Cecilia Bartoli: I can find no consistent approach or system to her vowel shaping. I get the feeling that she is a singer who relies on feeling (both emotional and physical) for her singing. There was significant lip spreading and lip rounding throughout, as well as a wide variety of levels of mouth opening. I think it would be interesting to watch Bartoli in a stage performance, from afar, because the dramatic changes in facial and body movement would make for good distance expression. The work with her face, jaw, and neck seems excessive, but she makes it seem easy, somehow. I really don't know how she does it. It seems that the vowels are shaped purely to fit whatever shape her mouth is in for any given expression.