How does the repetition of the word singing influence the overall meaning of the poem “i hear america singing” by walt whitman?

Repetition is used to emphasize hope and unity of Americans  

Explanation:

The entire poem rotates around singing because everybody is singing the hatters, the women, the carpenter, and the deckhands when reading the poem, you will feel like you are in a broad play singing and dancing. Therefore repetition of the song has been used to create unity and love among all people. However, based on the understanding of the Whitman, singing is a universal activity that each individual can do on their own, but when done in unison, it creates an intense meaning.

the reason some people sacrifice their own life for another person's life could be that they are in love with them and would do anything to keep them safe a protected even if that means risking their life in the process