This one made me a little sad: one of the greatest singers of the second half of the 20th century, German mezzo Christa Ludwig. She was 93. My favorite Ludwig story: when she announced she was going to retire, sometime in the 90s she said (I'm paraphrasing), "What am I looking forward to? Having two glasses of wine with dinner. Or getting a COLD. I can't wait to get a cold."
I'll give you three examples of her art, from the three pillars of a major singer's career.
RECITAL
Brahms, with Bernstein at the piano.
CONCERT
Mahler with Muti and the Vienna Phil.
OPERA
As Ortrud in Wagner's *Lohengrin." I don't know when/where this recording was made - - the listing on YouTube says it's Karl Böhm conducting but can we be sure of that? In any case, it's very exciting singing and the audience goes NUTSO.