I've attached a brf file of how I might approach some of these kinds of things. Keep in mind that this type of annotated music is not always best Brailled in our usual single-line format. Sometimes lists are better at explaining the lesson at hand, with music embedded in the literary context.
(this braille file is quick and dirty - I did no proofreading, so forgive any typos.)
Transcriber's notes are your friends in these kinds of books, too! Don't be shy in explaining what print is showing.