I've been watching one recently and was pretty sure he was a Northern Mockingbird (or a Townsend's Solitaire, but more likely the NM). Very loud, very happy, very good combining and making up complex songs about his 2-block long territory. I could easily hear him a block away. Likes to sit atop tall trees and inform the world that, Hey! It's morning! Everyone up and at 'em!. I saw him flying and there were white patches under its dark wings. What a long tail! No doubt helps him maneuver. Very likable bird (though there isn't one living near me to keep me awake at night...).