A Balancing Act (and its Dual) in Some Measures of Schubert

In much tonal music that is triadic and metered, stable events like tonic (I) triads and consonant (C) melodic tones tend to occur at relatively metrically strong (U) moments, and unstable events like dominant (V) triads and dissonant (D) melodic tones tend to occur at relatively metrically weak moments (/). However, in the “classical” variety of this kind of music, this synchrony is not overdone and is sometimes deliberately undercut; the suspension, which offsets these bedfellow arrangements, is a quick way to evoke a “classical” sound. The four-measure idea that begins each of the famous first two phrases in the first of Schubert’s Trois marches militaires balances synchrony (shown below with characters tracing parallel trajectories) with offset (shown below with characters tracing divergent trajectories); moreover, the means by which this balance is obtained is dual to that of the other phrase.

Something similar happens in an even more iconic classical melody, Beethoven's "Ode to Joy."