Recorded by fiddler James Morrison, August 10, 1935: https://archive.org/details/JamesMorrisonGranaualeBarnDance This was a duet with another, uncredited, fiddler, and very much not a unison performance; years ago when I learned this tune I settled on certain parts of their harmony to play on my own, you might have a different take on what the actual melody was, especially in the 1st part. This is a beautiful tune, and I wonder if it’s another Morrison composition, like his well known Skylark reel.
Gráinne Ní Mháille or Grace O’Malley was of course a 16th century freebooter who became an iconic figure in Irish folklore: http://en.wikipedia.org/wiki/Grace_O’Malley Her nickname is more usually spelled "Granuaile."
Kevin! Thanks for posting this. No kidding, this had to be a real challenge to figure out with the two fiddles playing. I offer this alternative take with the same disclaimer you offered: the second fiddle harmonizing makes it difficult to tell where the melody actually lies. I really debated about the ascending line in measures 3 and 4. I thought that maybe I could justify it because of the similar progression in the B part, measures 3 and 4. Nonetheless, you are the real hero in figuring this out. I simply changed a few things here and there, mostly utilizing your awesome transcription.