I may need you help identify another bird. It's not exactly rare where I live, but I don't know its name. The bird is rather small, black, except brighter-white patches at the very end of its spreading tail feathers. It has a very elegant way to move from branch to branch, where it usually turns 180°, almost like dancing. I thought this bird is of the silent type, but recently I caught it singing. Didn't have a phone with me then, but the melody was pretty distinct, so I could somewhat replicate it
here. Could you provide your thoughts?