I hear this thing around my backyard all the time, finally managed to get it on audio today (video actually, but the bird never made an appearance, so I just extracted the audio). It shut up and stayed invisible in the tree shortly after I moved out into the yard.
In NJ, we have a lot of mockingbirds. The sound is always a mockingbird there. I have no clue what bird yours is, but your geographical location would help identify.
So you.re close to the flyway and birds are already migrating early this year. I’ve seen many species leave already here. Possibly migrating hawks of some kind. Have they been here all year or are they new to the area?
I have heard the calls most days since early spring. Not necessarily the same birds the whole time of course, but that's too long a span for 'just passing through'.