My next door neighbour used to whistle in the garden a lot and a blackbird picked it up.
He died quite suddenly while I was up at university, and I had a strange moment when I came down in the holiday, hearing him whistling in the garden. Once I'd worked out it was the blackbird, I thought about how nice that is. Potentially, that blackbird will pass it on to its offspring and so on, and it will evolve, but it's a contribution to what you might call 'the oral history of the blackbird'.
Lovely story. But do blackbirds pass on songs or compose their own unique ones?
As a child I had a favourite blackbird I listened to for a couple of years - he either changed his tune after that, moved garden or died. He sang a perfect dominant 7th arppegio. I can't recall the key but it was something like this:
G B D.... G B D.... (keeping me in suspense) G B D F!
