Now, either he is senile, and doesn't remember his own music, because he wrote the music. Or he is actually transferring a very strong message to them, saying, "Come on guys. You have to play by the book.
Ahora, o bien está senil, y no se acuerda de su propia música, porque la escribió él, o en realidad les está transfiriendo un importante mensaje, que dice: "Vamos, tenéis que tocar lo que dice la partitura.