Maisy, one of our esteemed readers and contributors, wrote me recently with information about the Emma 1 "theme" music...
Emma 1 Music Notes by Maisy
I read recently that the piece heard during the opening and closing credits is called "The Twenty-Ninth of May." The tune is also heard during the ball at the Crown Inn (when Mr. Knightley dances with Harriet), as well as at the Coles' party. Mrs. Cole asks Mrs. Weston to play the pinaoforte so people may dance. The tune she plays is "The Twenty-Ninth of May." Unfortunately, though, we are deprived of a glimpse of the dancers.
I also learned that there is an English Country Dance of the same name...
[Kali notes: Though I haven't compared the dance notations below with the Crown Ball version of the dance from the miniseries, others have noted that the figures are not the same.]
Background info on the tune (you'll have to scroll down) :
So, it appears that this tune celebrates the Restoration of King Charles after Cromwell's disastrous Commonwealth, taking the king's birthday as its title! Thanks Maisy!