Dunno if "knowing" is part of the whole bit, it could perhaps only be an evolutionary thing:
-The more dazzling, astonishing sounds the male does - the more intuitively attractive he becomes to the females?

We don't have these up here at 60 deg N, merely blackbirds, starlings and nightingales. Still lovely jazz musicians.
Besides - many birds doesn't seem to have perfect pitch - many times I've fruitlessly tried to whistle replies to birdcalls,
but they still come at me wide open - trying to chase the "intruder" out of their turf.