How cool is this? Waving his tail attracts the lady birds.

Yale researchers note: "The courtship songs of the male Anna’s hummingbird are produced by his tail feathers during a steep aerial dive nearby the object of his affection."
But even better, according to a press release: "Yale University scientists show that the song - and therefore the mating success of the hummingbird - depends upon the exact aerodynamic relationship of two of the bird’s outer tail feathers."
This is the Sept. 9 issue of the journal Science, the statement says, and "Yale scientists use high-speed video in wind tunnels and animation to show how exactly how the feathers act upon each other to produce this song of love."
(Yale authors of the paper are Christopher J. Clark and Richard O. Prum, the statement said)

And you really can hear the quiet little love song in this really well-narrated video: