Bird songs are the sounds that birds make that sound appealing to humans.
Interesting!  WHat would be an example of it?
Any bird call or sound they make that sounds good.
Neat!  For how long have humans been doing this?
It is birds that do it, not humans.
Oh, I see.  I was confused.  Thank you for clearing that up.  Is there a particular bird that has a more appealing call?
Bird vocalization
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizations) are distinguished by function from calls (relatively simple vocalizations).
Definition.
The distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with courtship and mating, while calls tend to serve such functions as alarms or
entered into it. So it can sound like any musical instrument, or it can take sounds which aren't from music instruments, like a bird singing, and make that into a musical instrument." When asked what the Melodian could be used for, Mendell explained that, "A good example is what Stevie Wonder did with it in "The Secret Life of Plants"; he wanted to be able to have birds singing a melody which he wrote." Mendell was referring to the 1979 soundtrack album "Stevie Wonder