On this day in 1970 mezzo-soprano Marilyn Horne made her Metropolitan Opera debut as Adalgisa. 

Winthrop Sargeant in The New Yorker:

The Adalgisa of the evening was Marilyn Horne, who was making her Metropolitan début. It was high time this début occurred, for anybody who has been around singers knows that Miss Horne is, and has been for some years, one of the world’s most spectacular mezzo-sopranos. From time to time, with her younger and more expressive voice, she even stole the show from Miss Sutherland, and their duets, which they had sung together many times before in other opera houses, were beautifully coördinated – particularly the finest of them, “Mira, O Norma.”