The proposition has two parts: Part 1: All the various kinds... This explains that all the different orders fall under this overall order. Part 2: And this is the order... This explains how the musical notes, vowel signs, crowns and letters fall under this order.
Part 1: All the various kinds of functions found in the Sefirot are without exception governed by the order of the ten Sefirot… All the different categories we distinguish in the Sefirot apply to everything. Thus each Sefirah divides into ten Sefirot, for each Sefirah and every part of each Sefirah contains the entire order of government (except that in any given case the particular Sefirah in question has more influence). Accordingly, wherever we look, we will always immediately distinguish ten divisions corresponding to the ten Sefirot. Even when the lights need to divide in other ways in order to carry out their function, nevertheless everything must come under this tenfold division. Each of the different levels divides into its own individual levels, but overall they make up a total of ten levels.