It's time we relegate the myth of "fall cleanup" to the trash bin. Many, many songbirds depend on "yard leavings" to find shelter and food during north Texas' cool months - much like a bird living in a natural forest.
The majority of north Texas' wild birds are attracted to an unkempt yard - Wrens, Juncos, Brown Thrashers, Towhees and all our 12 species of native Sparrows, to name a few.
Of course, some accommodations need to be made for the humans living there too. At our house we clean up a portion of our yard, and let nature take its course in the rest of the landscape. We're constantly rewarded with visits from birds of all kinds.
The Macaulay library at Cornell University's Lab of Ornithology has collected thousands of bird sounds: they're accessible through their web site - www.birds.cornell.edu/macaulaylibrary . Their first recording of birds was made back in 1929, and many, many have been added since.