I lived with Irma and Stefan many years. One of the extraordinary things was breakfast time. They must have been both morning persons. The talk around the breakfast table would not be small talk whatsoever, not the weather, but on the highest aesthetics of his creative ideas and his composition, or the late Beethoven quartets. I remember a lot of analytical talk about music in general and about the classics. He was at the highest peak of inspiration when he was talking about this, and so was she just listening to him. Then she would say, "Aha! then this means so and so!" And then he would go on for another ten or fifteen minutes. I remember an atmosphere of such inspiration at the wealth of his ideas, his talking, and her listening with the greatest understanding, and responding to him in a way that he could go on and on. And this was breakfast. [...]
The difference of Stefan's music, the color of it, the vitality, the blazing non-legatos and staccatos, the excitement of it, that was what struck me the most in my youngest years. Not the harmonies, because my ears immediately responded to modern harmonies the minute I heard contemporary music. It didn't make one iota less my love and completely being encapsulated by Beethoven and Schubert. One of the things that Irma was constantly saying was that through contemporary music one understood the classics. It's very true, and I teach that to my students. [...]
I played the Chaconne of Stefan, Complaint, a little piece called Con Fuoco, and the Pastorale, which he dedicated to me. Those were the pieces I played when I was about twelve. I had a natural facility, so I just learned them. I played them for Stefan, but I guess I worked on them mainly with Irma. I don't remember instructions, and I don't remember any differences of their opinions. It's a pity that I played so many of his things in first performances and cannot remember his comments in our rehearsals. I cannot remember, because it seemed always to me that he didn't say very much. He listened very carefully. He must have known every single thing we were doing, which might not have conformed to his imagination, but he didn't tell us that it didn't. It was as if he accepted what every person did (I'm talking of the chamber works, of course). What one got from him was the spirit of a piece, and the enthusiasm, the élan of his music. And that was conveyed just by his personality and his being next to us at the rehearsals. Because he sang along, and of course he indicated tempi, which is the most important thing. So we were not wrong in tempos, or, if we were, that would be corrected, but not very strictly. I remember in the Trio for Flute, Cello, and Piano he thought we took the second movement too slow. But we said we liked it better that way. I don't remember if he shrugged his shoulders or made a remark, but we continued to play it slower than he had wanted, because we felt that that was better. There was otherwise not enough of a contrast between the first movement and the second.
The one thing I remember Stefan saying over all the years was the one word "More! more!" And that word will be forever burned into my memory, because that was the word he used almost exclusively. It sounds sort of idiotic, but he was always asking for more expression and more deep intensity into what I now understand as the vitality of his music. If you weren't awake to that, it wasn't the music. And I think that tempo and that "more!" were the basic two things that he did, plus the all-important spirit of the piece. I'm talking about the Saxophone Quartet, mainly. I don't know if I even looked at the metronome. I was just with him all the time, so I knew the tempi that he felt. I suppose, if I was wrong, he corrected me. Technically I could do it, and we had very fine players. [...]
He talked to his adult pupils on a one-to-one, very equal basis. He never was "the professor." His students were always close friends, or they became equals at least in his social attitude, so could say whatever they wanted, and they did. You don't find that with other teachers of composition. I studied later with Roger Sessions, and if I said what I felt like, it was couched in very civilized terms. Stefan was a very accepting person. I don't know how critical he was. He loved people so much for their individuality and those things they had that others didn't have. He surrounded himself with very extraordinary people and loved them for their qualities. If you were his friend, you were wholeheartedly his friend, and he gave heart and soul to you. I didn't even realize until after his death what a warm person, or hot person he was in friendship. It was just complete acceptance and all-embracing. Maybe I was an exceptional case without realizing it, but that was my position with him.
Interview: AC, Boston, 10 November 1983.