Ah, C Dish,of course it was understood, even by me, but my contributions may end here. I wonder if works of jazz might feature in these firsts? (Maybe that should have been reply #23)
I have no doubt that jazz will provide a great number of harmonic innovations whose exact moment of first appearance may at times be easily pinpointed, though not necessarily by me. That requires an anorak of a different order.
As we go back in history, the problem becomes much thornier, and surely only inconclusively solveable, as not every work ever written survives -- still, there must be generally agreed-upon lines of provenance that, for example, led to the particular pattern composed by Mr Storace. I can certainly tell that his Passagaglio <sic> owes an enormous debt to Frescobaldi, in whose oeuvre however, AFAIK, no such sonority comes about despite a seeming penchant for just such skirtings of the rules.
Here is something I would love to see explored: When did composers begin thinking of the harmonic cycle of fifths as being an actual cycle in practice? I know that this happened in stages, of course, but that in spite of such demonstrative examples as the Canon per tonos from the
Musical Offering it wasn't until perhaps the 19th century that a great digression such as the modulation by a major third could be seen to occur three times in a row in the same direction. Schubert's G major String Quartet moves for its second subject first from D major to Bb major, then from D major to F# major, but the 'obvious' link from F# to Bb by the same modulatory 'operation' doesn't take place. Not that he didn't know about the possibility, of course, but because, I suppose, he disdained it for its formal or affective inutility.
If it seems like I'm bandying about with highly technical terms, rest assured that they're not such but rather everyday words applied to a topic for which I lack the suitable vocabulary.
