At first, I was thinking of Stignani shredding her voice in the famed “Condotta ell’era in ceppi,” live from La Scala in 1953; and then Margaret Klose (not sure if she is technically a contralto) leaping out of the speakers with her witchy Ortrud live from Berlin under Heger in 1943 (alas, she is singing with Nazis Volker and Muller, and apart from her, all the singers sound stressed).

But after much reflection, and I hope this selection meets the requirements. (It is a selection from a commercial recording; I could not find the whole recording on youtube, but someone uploaded it in parts.) The inimitable, redoubtable “ball busting” Rita Gorr unleashes volcanic power (a fire that will merge the stormy sea in a terrifying denouement ) in her recording of the falcon role Margared in Lalo’s Le Roi d’Ys. Here is a Margared who becomes an Ortrud (and her duet with Karnak resembles the infernal plotting of Telramund and Ortrud in Lohengrin). This recording reveals prime Gorr before the top collapsed way too soon in the mid 1960s. The voice is of a piece here from scary chest to opulent middle to a piercing, sopranoish top. Watch out, Ys and your denizens: don’t mess with her. She’ll get you and your little flood control system too.