Chose one or more of the chapters of The Souls of Black Folk and discuss the significance of the quote and song with which the chapter begins. To do this, you will need to find a copy of the lyrics to the sorrow song and identify the context from which the lines of poetry are taken.

In chapter three of The Souls of Black Folk, Du Bois focuses on the work of his famous contemporary, black leader Booker T. Washington. While Du Bois tries to be evenhanded in his treatment of this leader, crediting his achievements as well as his failures, Du Bois is, in the end, harshly critical of Washington. He condemns Washington for what Du Bois considers to be servile capitulation to white racism. He criticizes Washington for giving up on pursuing the vote for blacks. He also criticizes him for encouraging blacks to be abject and accept the white evaluation of them as inferior, which he says saps blacks of their manhood, and he criticizes Washington for supporting trade school training for blacks over higher education.
The section of the poem that heads this chapter is from Canto 2 of Lord Byron's Childe Harold's Pilgrimage. Du Bois points the reader to lines 73–84. The long poem as a whole is apt for this chapter, as its tone is one of disillusionment, weariness, and bittersweetness following the heady days of the French Revolution, expressing sadness at a time when revolutionary fervor has quieted down. This mirrors Du Bois's sentiment that Washington represents a sad and weary tamping down of the blacks' former fervor for equality.
This idea is made clearer in the specific passage from which Du Bois quotes. In this passage, Childe Harold comes to Greece and surveys what is going on with the struggle for Greek independence. Like Du Bois, Childe Harold sees the glory days of the struggle for independence, when greater men were in charge, as gone. Harold both criticizes the abjectness of the current Greeks—as Du Bois does Washington and his followers—and yet recognizes, like Du Bois, that people who are used to being ground down can have a hard time mustering up the will to fight back against oppression.
The particular lines from Canto II that Du Bois quotes summarize his critique of Washington's policy of accommodation and servility and offer an antidote:

From birth till death enslaved; in word, in deed, unmanned!
[. . .]
Hereditary bondsmen! Know ye notWho would be free themselves must strike the blow?

Just as Byron is saying that the current day Greeks are "unmanned," so Du Bois argues that the present day blacks are "unmanned" by Booker T. Washington. Du Bois contends, criticizing Washington for narrowly pursuing economic interests, says that

manly self-respect is worth more than lands and houses, and that a people who voluntarily surrender such respect, or cease striving for it, are not worth civilizing.

Instead, Du Bois believes, as Byron says,

Know ye notWho would be free themselves must strike the blow?

Like Byron, and in contrast to Washington, Du Bois argues that blacks have to rouse themselves to stand up for equal rights for themselves, instead of hoping that being nice, as Washington counsels, will get them what they want and need.
Byron's poem is an almost perfect gloss for this chapter. Further, the fact that Du Bois has the education and cultivation to quote Byron challenges Washington's ideas that blacks should simply settle for less in terms of educational opportunity.