I can do pretty good impressions of birds. Do you know about that? 
Can you do both bird calls and bird songs?
Yes I think I do both. What is the difference though exactly?
In birding, songs are distinguished by function from calls.
That's pretty interesting. What kind of functions are we talking here?
The difference between songs and calls is a matter of complexity, length and context.
What birds have really complex songs and calls?
wrens are small and rather inconspicuous, except for their loud and often complex songs. Notable exceptions are the relatively large members of the genus "Campylorhynchus", which can be quite bold in their behavior. Wrens have short wings that are barred in most species, and they often hold their tails upright. As far as is known, wrens are primarily insectivorous, eating insects, spiders, and other small arthropods, but many species also eat vegetable matter and some take small frogs and lizards and many more amphibians.
Etymology
his hand around my shoulder, and he said "I think we are together because we're both similar, like we're both really messed up" and I thought it was the saddest thing I'd ever heard. And I said, "I'm not sad, I didn't know that's why you thought you were relating to me on that level, I'm actually doing pretty good". And he was upset, and that's when I wrote the song. I thought, I had to do so