"How long should the advanced pupil practice?" Professor Auer was asked.
"The right kind of practice is not a matter of hours," he replied.
"Practice should represent the utmost concentration of brain. It is
better to play with concentration for two hours than to practice eight
without. I should say that four hours would be a good maximum practice
time--I never ask more of my pupils--and that during each minute of the
time the brain be as active as the fingers.