Key lessons are identified and are used to lay down important foundational lessons for all future grades.
As an added bonus, we also include all of the previous key lessons from the earlier grades.
To make this clearer for you, the Grade 4, Week 9 example seen on the right, indicates a lesson with harmony. Just in case you had forgotten part of the Grade 3 lessons regarding harmony, they are also included as a supplement for Week 9.
At all levels of theory this is a clear added advantage in many useful ways.