A four-voice, polythematic imitative fantasia in mode 1, with quite extensive sections of free counterpoint. Despite the looseness of structure, the work is quite pleasing and falls well under the fingers. There are some oddities of detail that need some rectification. The formal structure seems to show regular groupings and a balanced approach to sectionalization: the work is 129 compases (65 transcription bars) beginning with two exactly equal 24 bar sections and a shorter third section: I (1-24), II (25-48), III (49-65).
I – theme 1: B/A/T (partial) > free > K. Bars 10-24 are free polyphony with full texture throughout, but some writing a3. (A secondary theme is introduced at b. 17)
II – theme 2: A/S – B/T > theme 3: A/S at same canonic interval of time and pitch > B/T duo with B derived from 2 and Free T > 4 free bars a3 > 4 free bars a4 K.
III – theme 4: B/T – S/A free with two B entries derived from 4, then free to final K.
Formula:
I – expands quickly to thick texture which is maintained [1 theme]
II – concentrates on duos a3 a4 phrases [2 themes]
III – B/T duo > full texture to end [1 theme]

Free passages have much more quaver movement, and while not imitative are complementary and help aid the forward thrust of the music. The formal idea is important. In section II – themes 2 + 3 are related – both have common features in their shap, based on a pattern of an ascending 2nd followed by a descending 3rd (+2-3) all in minimas (crotchets in transcription).