Well done all of you for guessing almost all the correct identities of the mysterious Ortruden. The identity of the winner (and of all 13 howling witches) will be revealed after the jump.  

The most nearly correct guesser is Feldmarschallin (not pictured) with 12 correct out of 13 and an earlier timestamp than the similarly approximate stevey.

And the 13 Ortruds, in order, were…

1. Christa Ludwig Teatro Colon 1964
2. Christine Goerke Houston 2009
3. Evelyn Herlitzius La Scala 2012
4. Eva Marton Met 1984
5. Margaret Harshaw Met 1959
6. Rita Gorr Bayreuth 1959
7. Elena Nicolai Naples 1954
8. Astrid Varnay Bayreuth 1954
9. Deborah Polaski Met 1998
10. Waltraud Meier Berlin 1993
11. Ruth Hesse Tokyo 1970
12. Ursula Schröder-Feinen Bayreuth 1972
13. Marjorie Lawrence Met 1935