From the latter's admirable division of the dances into those that exist in Schubert's hand (Bd. 6) and all those published in his lifetime (and those published posthumously but which can be traced back to Schubert) (Bd. 7), one can find support for my rough division of the dances into three groups (before 1821, 1821-23, and 1823-28). In the main, the earlier dances were collected for publication from a number of ms. sources, where the later publications may have been newly composed pieces planned as sets. The first of these "planned sets" seems to be D 734, but D 779 is an anomaly as the ten existing in Schubert's hand were chosen from two different ms. collections, the majority of whose dances went into other publications or remained unpublished till after Schubert's death.
The two graphics below (1) give a view of the relationship between D146, D779, D783, and D973; (2) chart the positions and keys of the ten dances in D779 in their sources (the 9 German dances and 17 German dances). Both graphics are thumbnails; click on them for the original, larger versions.
