In January 2011, Milton Babbitt died and I was conscripted by New Music Box to write an in memoriam article about him. The piano concerto I was writing exactly at that time ended up being written in his memory; I had been thinking of dedicating the piece to him as a 95th birthday tribute, but this is how things go.
In that article, I mentioned that I had already written birthday pieces for him, every tenth year just like clockwork. I had dedicated my big wind ensemble with ten clarinets piece Ten of a Kind to him as a gift for his 85th birthday, and in that article I paraphrased his written response to receiving the score as best as I could remember it (I was writing it in France). Ten of A Kind is very big and very complicated, and the "President's Own" did an amazing job with it.
I have just located a scan of the actual letter he sent, which just goes to show that he did tend to keep going when he wrote you friendly letters. I had not remembered him calling me "Dear, Dear David"; I also had not remembered that he told me he had nominated me for something. And so almost twenty years later, here it is. It seems to be the only letter I have from him that doesn't end "As ever, Milton".