Well, first he needs to know Mendelssohn's techniques. Then, once he has an understanding of Mendelssohn's techniques, he will have to create a rough draft of the piece. Then, if and when he makes any edits and revises, he will be able to create his final piece.
English morphological rules detail how words relate to other words. Thus, my best assumption would be because BOLDEST is an adjective whereas BOLDLY is an adverb.
