Soundtracks: Songs that Defined History recommended the documentary series by the same name. This series takes eight key events in recent American history and highlights how popular music shaped these events and defined the collective memory of them.
If you wish to use a song as a historical source a really useful resource is Making Sense of American Popular Song by John Spitzer and Ronald G. Walters.
John and Ronald suggest that we use a framework of questions when we want to use popular music to understand the past.
What is the song?
What is the basic, musical work?
What are the renditions (publication, recording, performance) of the song?
Who created the song?
Who wrote the music?
Who wrote the lyrics?
Who else created the song or rendition of the song?
What is the song’s structure?
What is the metric structure of the text?
How many words to a line?
How many lines to a stanza?
Are lines of the same or different lengths?
Do the ends of lines rhyme? If so, what is the rhyme scheme? Are there internal rhymes?
Does the song use alliteration or assonance?
Is the song strophic—does the tune repeat over and over with new words?
Is it through-composed—neither words nor music repeat?
Does it have a verse-chorus structure, the tune repeats in the verse with new words, but words and tune both repeat in the chorus?
Does the song have a memorable phrase?
What was the song’s historical context?
What are the factors that are relevant to understanding and interpreting the song at a particular moment in history?
What is the primary context? That is, what was the context at the time the song was first created?
What is the secondary context? That is, what are the contexts of the song at subsequent periods from the time it was created to the present?
What does the song mean?
What do the words mean?
What is the implied meaning of the song?
How have performances of the song influenced the meaning of the song?
How have people interpreted the song? What have they said about the song?
Is the song considered to be a good song?
What can the song tell us about people and society?
Does the song express shared values or experiences and emotions that help define a group’s identity and solidarity?
Does the song, the singer or the genre help people construct self-images and provide models for how to behave?
Does the song express judgments about lifestyles, values, and appearances?
Does the song relate to other popular texts?
Does the song have multiple interpretations?
Does the song serve as a forum for public debate about manners, morals, politics or social change?
Are there other questions that could be added to this framework?
Music students about 1903-1906