Among Schubert's dances in triple meter are about 130 Ländler, composed between 1815 and 1826 and by and large preserved in manuscript sources. In contrast to the schottisches, german dances, and waltzes, however, the Ländler do not appear among Schubert's albumleaves or dedication compositions, and thus it is not suprising that these dances are rarely mentioned by the composer's friends and acquaintances. Furthermore, as two journal entries by Franz von Hartmann indicate, Ländler were commonly confused with German dances. (In both instances, the reference is to Schubert's "16 Ländler, opus 67" D734, which were published by Diabelli in December 1826 under the title "Hommage aux belles Viennoises: Wiener-Damen-Ländler.")
17 December 1826 (Sunday): By Spauns, where Gahy played brand-new Schubert German dances (with the title "homage to the belles of Vienna," which made Schubert quite angry).
6 January 1827: We went to Spauns, where we were invited, along with Gahy, to breakfast. . . . then Gahy played two superb sonatas by Schubert and the German dances that had enchanted us so at M on the 17th.
Hartmann probably should have known better, as few collections outside the first dozen or so numbers in D365 and D779 represent the Ländler style more consistently, but in his defense we should remember that Deutscher was not only the genre title for a particular group of dances and their musics, but also the family name for all "waltzing" dances.
Several points can be made about D734, many of them reminders of earlier posts:
(1) the boundary between Ländler and Deutscher was always fuzzy with respect to musical style in the urban dance cultures, being reduced by the 1820s to sweeter/quieter/slower (Ländler) versus formal/louder/faster (Deutscher).(2) in dancing, the types were often intermingled to fit alternations between couple and group dancing. In D734, for instance, n2 comes as close as any Schubert dance to realizing the type of the rural Ländler in the late 18th century: D major, I and V only, violinistic melody with many third doublings. But n16 is clearly a Deutscher that would accompany the obligatory processional that ended an extended dance/cotillion.(3) the "sweeter/quieter/slower" criterion is muddied by imitations of the Schnadahüpfl episodes in rural dancing. This alternation is clearly at work in D734n1: the first eight bars of Ländler are interrupted by the same music abruptly transformed into a loud, drone-accompanied Schnadahüpfl, then the Ländler returns. Remember that this is also what happens -- down to the direct mediant key shifts -- in D779n13 and D145n7.
Reference.
Litschauer, Walburga, and Walter Deutsch. Schubert und das Tanzvergnügen. Vienna: Holzhausen, 1997.