In your contract, I suggest that you bring the terms and expectations you have. Let me give you some for examples:
Salary: $125-150 a week with a 2% increase every year (just an example)
Any additional fees that you have
Powers that you would like (In charge of developing music, appointing directors/directresses)
Days you want choir rehearsals
I hope that this information for this contract helps you, but use those ideas and develop from that.