http://library.globalchalet.net/Authors/Poetry%20Books%20Collection/So%20Long!%20Walt%20Whitmans%20Poetry%20of%20Death.pdf Harold Aspiz points out in his book, "So Long! Walt Whitman's Poetry of Death: Walt Whitman's Poetry of Death" that people spanning back as far as the Greek poets have desired to translate bird song into poetry. While they and Whitman didn't have tape players, CD's, or I-Pods to replay the songs, we can easily relate to both the happiness the mockingbird experiences when with its mate and the incessant but futile calls when it's mate disappears. https://muse.jhu.edu/book/2301 Aspiz, Harold. So Long! Walt Whitman's Poetry of Death : Walt Whitman's Poetry of Death. Tuscaloosa, US: University Alabama Press, 2011. ProQuest ebrary. Web. 25 April 2017.