Then if he went on playing, dwelling on a fixed idea, changing and loosely shaping it, someone would ask:
"What is that?"
"Nothing," answered the player. ...
"How can it be nothing," the other answered back, "since you are playing it?"
"He is improvising,"...
"He is making it up, can't you understand? He just thought of that this very minute."
"How can he think up so many notes right and left at once, .. and how can he say 'It is nothing' of something he is actually playing? One surely cannot play what is not?"
Thomas Mann in "Doctor Faustus" (1947)