1. The simple progression using I and V7 (characteristic of the traditional Ländler) is used in the C#-major section.2. A common way to vary the I,V7 patterns is to introduce a third chord, IV, typically generating a progression either I-IV-V7-I or IV-I-V7-I. A variant of the second of these substitutes ii (especially as ii6) for IV, as in D779n13.3. Another common way to "enhance" the I,V7 patterns is to introduce suspensions or appoggiaturas (see the Ländler by Hummel in this post for examples). Schubert, of course, makes leisurely two-bar suspension figures the hallmark of D779n13. (If the slow pace seems to hint at the sacred style, then it would be only in jest, given the parallel fifths that underly the progression.)4. Improbably, the Ländler style is "enforced" by the rare expression mark, "zart," and verified by the Schnadahüpfl episode in the C#-major section.
Although Schubert's friends might very well have enjoyed the piquant sweetness of this waltz's first strain, they might equally have shaken their heads over its stylistic oddities.
