"Blackbird singing in the dead of night..." as the second most popular surviving Beatle sung all those years ago, in a voice which my father found harsh and strained - unlike the blackbird's.
I once placed my self equidistant between two singing male blackbirds during one of the two times of the year they sing most melodiously (spring and winter), and I swear I understood what they were talking about - almost - though I was quite sober.
One bird throws a melody to the other, and the other takes it up, changes and embellishes it slightly, then sings it back to the other. They keep this up from dusk 'till dawn, for weeks on end. They do not sleep.