I don’t see a reason to think it’s not a Blue form bird. Either way, it doesn’t show any mottling on the crown, and the plumes appear to be dark, though we would need better photos to be certain if that.
The spur on a GWTE is behind the head, and is vertical. Unless it’s an Eurasian, then the horizontal stripe is along the flanks. Even if that white isn’t reflection, as I think it is, it’s in the wrong location.
Weird, the links up above brought me to different sound files. That’s why I couldn’t hear what @Quiscalus quiscula was hearing! These new files are not CHSP. Maybe Eastern Towhee?
I think you might be hearing a combination of songs from the “CHSP” , Song, Blackbird, and whatever the whistler is (too low for Titmouse, maybe BAOR). I’m having trouble hearing any rising high frequencies.
Can you find any similar examples on Macaulay? To me the first song is the rising portion of the GCKI song. The second is an odd song variation. Brown Creeper has a much sweeter song that lacks the rising portion at the beginning, instead starting with a trill.
They have a surprising repertoire of trills. Of the other trillers, DEJU is much more complex and higher pitched to me, Eastern Palm is super dry, PIWA is low and sweet. Plus it’s in a cemetery.