You are correct. The top note in this recording is E-flat, down a half-tone from Delibes' original. Miss Sutherland stopped singing top E-naturals in public in the mid-1960s. She sang E-naturals in her early live performances of Beatrice di Tenda and Semiramide. She even sang up to High-F in her early performances of Mozart's "The Impressario" and "The Magic Flute". On her recording "The Art of the Prima Donna" she sings this aria in the original key. I am not a singing teacher (or psychologist) so I have no clue why she lost the confidence to sustain a high E-natural in front of a live audience.

@@sutherland9 As a veteran singer I can say the voice is ever-changing, and the very highest notes can lose some quality...even if a singer can still reach them. Dame Joan always wanted to deliver high quality top notes..."Nice ones" as she described them. Also, a higher tessitura means higher demands on energy, so singing slightly lower saved energy and strength.

Where do you find these wonderful gems? Thank you so much for posting this!!

The one she did in Atlanta in 1966 seems to be in D natural throughout, and this was one year before she made the Decca recording in E flat. She might have been experimenting with the keys to decide which one suits her the best. kzfaq.info/get/bejne/ephzirpi0ZiceYk.html

She sang it on the Art of the Prima Donna in the original E natural - I thought stunningly. In the late 60s performances and the recording she sang it down half a tone. I'm not aware that she sang it any more transposed than that. Eflat for stage appearances in Sydney in 1976. Pitches do, however, vary a little around the world but she didn't sing this aria in her concert rep beyond the late 70s I think.

@@ahogbin2644 Her staccatos are odd in the Art of the Prima Donna recording and so is her final high E. At some point during the staccato part the microphone appears to have been positioned too close for a couple of seconds. I much prefer the Decca version in E flat despite being in the lower key. She seems to have gained confidence in staccatos and high notes by the end of the 1960s. She may not have sung the aria as such in more than two keys but for the opening vocalise I count at least 3 different keys. And if the Atlanta recording is correct then apparently she did singthe entire piece in D at least once.

I don’t think she ever sang it in D natural. If you listen to the other pieces on the Atlanta concert, everything is a half step under her usual performance keys, so I think that one was just transferred incorrectly. Interestingly enough, she and Bonynge seemed to often bypass the key of D natural (and G natural, with the exception of late Traviatas) when transposing. Lucrezia and Lucia wound up in D flat, and Semiramide and Puritani wound up in G flat. They probably felt the flat keys sounded “warmer,” but I feel like it often made the cavatinas too low!

@@anthonygarza2017 Thank you for the information! I didn't know Sutherland and Bonynge preferred flat keys. She does sound too low in all her transposed stuff but I thought that had to do mainly with the fact that the sound of her voice is already darker than a typical coloratura soprano so the lower key adds to the darkness.