Thanks to both! David, I remember you from the old eskimo list.
I seem to remember from my college days the talk of what exactly distinguished a "passacaille" from a "chaconne", and just when we thought we had it pegged, an example would surface blowing our distinctions away. Basically, this wiki entry comes to the same conclusion that we did before the digital age:
The passacaglia was redefined in late 1620s by Italian composer Girolamo Frescobaldi, who transformed it into a series of continuous variations over a bass (which itself may be varied). Later composers adopted this model, and by the nineteenth century the word came to mean a series of variations over an ostinato pattern, usually of a serious character. A similar form, the chaconne, was also first developed by Frescobaldi. The two genres are closely related, but since "composers often used the terms chaconne and passacaglia indiscriminately [...] modern attempts to arrive at a clear distinction are arbitrary and historically unfounded". In early scholarship, attempts to formally differentiate between the historical chaconne and passacaglia were made, but researchers often came to opposite conclusions. For example, Percy Goetschius held that the chaconne is usually based on a harmonic sequence with a recurring soprano melody, and the passacaglia was formed over a ground bass pattern, whereas Clarence Lucas defined the two forms in precisely the opposite way. More recently, however, some progress has been made toward making a useful distinction for the usage of the seventeenth and early eighteenth centuries, when some composers (notably Frescobaldi and François Couperin) deliberately mixed the two genres in the same composition.
David, I'll share a dirty little secret with you: the tuning is DAdgad. Playing common chord shapes in a different tuning was the springboard in this case. Our hymnal shows the tune in F minor, but it sounded too tinny capo'd on the 3rd fret, so I dropped the capo to the 2nd fret-sounds in Em. I am proud of the composition, but I feel like the tuning and the notation software did most of the work for me.