When the keynote speaker stepped to the podium a hush fell over the auditorium because we knew this guy was good. He leaned towards the mike and said “This is a sentence.” That’s the next thing he said, too: “This is a sentence,” over and over. For his entire 45-minute lecture that’s all he said, but each time he spoke it was different from every other time: a difference in inflection, volume, or timing. It was like John Coltrane playing the two bars in My Favorite Things. We were enraptured. When he finished everyone applauded, and there were no questions.