Music for Little Mozarts Lesson Book 4. A Piano Course designed for 4-7 year olds. Lesson Book 4 is the last in the Music for Little Mozarts series. After a review, the new concepts taught are: Flat and sharp sign; Tie; Crescendo and diminuendo. After reviewing C position and Middle C position, G position is taught. All three positions are used alternately throughout the rest of the book, with flat and sharp notes incorporated.