Firstly, perhaps the greatest singer to have emerged from the British Isles (almost certainly the one with the rarest technical equipment): Welsh Tenor Stuart Burrows, singing the Handel aria "Waft her Angels" with piano accompaniment.
Listen for the contrast between powerful and soft singing, the breath control (unsurpassed by any tenor ever, probably); and the way that (and this is very rare among tenors) after he has climbed towards a high note, when he hits that peak note his voice opens-out; and he can do this whether singing loudly or softly.
The actual aria begins at about 3:30 minutes
And now, simply the best operatic singer that lived during the recording era: Joan Sutherland - a more beautiful sound and a better technique than anybody.
Accompanied (superbly - was there ever a better accompanist with the orchestra?) by her conductor husband Richard Bonynge.
This is the Victorian operetta ballad 'I dreamt I dwelt in marble halls' with music by Balfe and words by Bunn.
It would be worth looking at the words as you listen since Sutherland sacrificed diction to the Bel Canto idea of continuity of tone production... i.e. she slurred the words...
This little song is a perfect fusion of music and words - and an example of how sometimes the summit of artistry is attained just one-off, by otherwise minor artists.
I personally find this so beautiful as to be almost unbearable - when listening last night I crossed over that line between crying and blubbering, and it took a good while for me to recover.
Well, here goes...