I learned about Song Sparrows last summer, when Paul noticed that someone outside was singing -- over and over again -- what sounded a heck of a lot like the first few notes of "La donna e mobile" from Rigoletto. (You know: da da da DA-da-dum. That song.) When we finally located the source of the song, we found a little brown bird that turned out to be a Song Sparrow. That was when I learned that (1) all sparrows are not House Sparrows, and (2) sparrows are actually pretty cool, and not, in fact, the boring drab birds they appear to be.
This Song Sparrow was sitting at the top of the lilac bush at the front of our house this morning, loudly declaring his right to this territory. (No one challenged him.) This individual wasn't quite as operatic as the bird we heard last summer, but still very impressive in his vocalizing. (From what I've read, every Song Sparrow has its own personal repertoire of songs, although they all share some general patterns.)
If I could figure out a way to record sound and post it here, I would do so, but for now you'll just have to imagine tunes coming out of that little beak.