Haha I was about to say- I'm pretty sure Martin Katz is "friends" with NO ONE! Scary man, albeit an incredible teacher. Jose, did you study with him?
Well, I'm sure that Frederica Von Stade and Marilyn Horne would consider him a friend.

-I took a few master-classes with him in DC many years ago. He was "strict", but funny, good-humored too. -And I still want his "cheat" for Mozart's "Exultate Jubilate"!