That is 12 hours on a saturday

I am being judgmental.  That is 12 hours of hard work on a Saturday. 

Why there is another piano class immediately after a piano recital?  Where is the lunch break? where is the travel time?

Even if this is what the child demented and planned, I would have either cancelled  or rescheduled some of these practices or classes, and focus on the well being of the child, focus on the activity in the morning and the concert in the evening, and added a long time for lunch break. Sometimes, we parents have to say "No, I do not want to".