The mockingbirds and catbirds I’ve heard are easy to identify, not from a particular sound but from how they string sounds together. It seems to me they copy notes, but not songs.
Yep, exactly. Around here we have a bunch of mockingbirds and blue jays, and you'll here the mockingbirds adopt some of the harsher sounds of the blue jays, but they usually surround them with melodic trills. It makes for a pretty dynamic contrast - reminds me of a Jazz solo.
