Hey Steve, I think Buddy might be onto something... It could be one of the several Mimids in the area, like a Mockingbird? I'm not up on your area birds, however, my wife lived in NYC for about 5 years and she had a Mockingbird that grew up in her neighborhood (East Village) and could sing every car alarm within a 5 block radius. Including mine! Mine was the last on his expansive repertoire.

Just a thought,
Dave