More Perfectly Contrarian Counterpoint in Berlioz's Symphonie fantastique

Last month, I pointed out a spot in the fifth and last movement Berlioz's Symphonie fantastique that uses successive parallel octaves. As shown in Liszt's solo piano transcription below, there is another spot in the previous movement that dwells upon perfect harmony between the outer voices, but in contrary motion. It's during the moment when the march to the scaffold first bursts forth with the entire orchestra playing fortissimo:

I hear this moment as pointedly transgressive of classical norms, which seems appropriate for music meant to accompany the opium-drugged artist witnessing his own execution, as Berlioz's own program notes describe the scene. There are innumerable examples of a diatonic progression comprising at least three chords in Western classical music in which 1) one outer voice moves by step in one direction, 2) the other outer voices alternates skipping by thirds and fourths in the opposite direction, and 3) the two voices always form imperfect harmonies. Below show 56 (7 x 2 x 2 x 2) possible versions with three chords, categorized by 1) the scale degree the stepwise line starts on (7 options), 2) whether the stepwise line goes down (d) or up (u) (2 options), 3) whether the stepwise line is on the bottom (b) or top (t) (2 options), and 3) whether the first melodic skip is a third (3rd) or fourth (4th) (2 options). I like to call these imperfect wedges.

Left out of the categorization is what mode (major or minor) the music is in, how the outer voices are harmonized, any transposition of one or both voices away from the other by one or more octaves, and so forth.

At least one of these progressions has been named: what the labeling system above designates as a 3ut3rd (for "stepwise line starts on ^3, goes up, and is on top; skipwise line starts with a 3rd"; it is enclosed in blue above) has been called the "champagne progression" by music theorist Gene Biringer and promoted at Open Music Theory. There it is recommended to "[o]nly use it with mi–fa–sol (or me–fa–sol) in the melody." Below each progression I have listed the number of instances of the progression I have found in a broad survey of Western classical music. While 3ut3rd (that is, the stepwise line starts on mi or me) is by far the most common of all of the ut3rd progressions, other ut3rd progressions are also used, particularly 1ut3rd. Moreover, the "champagne progression" is not the only imperfect wedge I would recommend as a schema: in my survey, 1db3rd (99 instances; enclosed in red above) is even more common than 3ut3rd (73 instances).

Berlioz, however, uses a perfect wedge: the same design but the outer voices are a third farther part. (I suppose you could call it a 4ub3rd perfect wedge.) Perfect wedges are much rarer in Western classical music: while I found 250 imperfect wedges in my survey, I only found 13 perfect wedges, including Berlioz's. This situates it as both atypical and perhaps also impertinent, since its design so closely resembles that of an imperfect wedge. Furthermore, in the Symphonie fantastique passage cited above, Berlioz's displacement of a third interval from more normative schematic counterpoint occurs at the same time as his displacement of the onsets from the strong beats of the meter.