In this first post I'd like to talk about Pierre Philidor's notation of ornaments and what this might mean. The ornament in question is the grace note leading up to the second quarternote in the third bar:

Seeing just the upper voice and that second bar, I'd think this is inégal. However, as this is french late baroque music, we would assume that inégal would be written in quavers like the fourth bar in the bass line. But if we can expect a regular inégal, why would Philidor then in the next system write the dotted figure seen in the upper voice first bar and bass second bar in the following example?

It seems like Philidor likes to play with the sharpness of the inégal. But if this is the case, we still haven't decided what the second bar in the first excerpt means. My personal take on this is to see what Vivaldi is doing at the same time. Shame on me for thinking about italians when working with french music, but hey, Philidor and his fellow french composers were more influenced by italians than the previous generation composers would have allowed. Vivaldi uses such grace notes as dissonances in front of the harmonically correct notes, and since we know that they should have at least half the length of the note, they become great dissoances while it's easy to read where we're going harmonically. So I tried playing it lombardic, but I'm not sure that this would be a great solution either.