Michigander in Mass

Hey, I said "random musings," right? So, that said, there's this bird that hangs out (maybe even nests, but I can't find it) in a sycamore tree right next to the Malden T stop that I use every day. It has the most incredible vocabulary I've heard in a bird. It's definitely a "city bird," as its call is oddly reminiscent of those multi-tonal car alarms usually set off by passing trucks and, um, trains. But in addition to the car alarms, it's picked up every other bird chirp it's ever heard in its life. It sounds like a very well coordinated, polite bunch of different birds in the tree--"oh no, you first," "ah, thank you old chap" kind of thing. The tree is in plain view of the platform, and anytime I hear it, I try to find the bird, but never can. I half suspect a camera and a loudspeaker somewhere, the joke's on me thank you very much. But so far, no luck confirming either possibility.