I know two kinds of audiences only--one coughing, and one not coughing.
When a piece gets difficult, make faces.
Sunshine can burn you, food can poison you, words can condemn you, pictures can insult you; music cannot punish - only bless.
The sonatas of Mozart are unique; they are too easy for children, and too difficult for artists.
It is not music's function to express rational necessities.
Practice in tranquility.