Both Douglass and Du Bois speak of the slave songs, which Du Bois calls "Negro folksongs" as songs of lament and hope. Douglass, however, adds the complexity to his analysis of emphasizing the emotional content of the songs, and his own eyewitness experience of them as a slave.
Douglass states that
I have sometimes thought that the mere hearing of those songs would do more to impress some minds with the horrible character of slavery, than the reading of whole volumes of philosophy on the subject could do.
He describes them as "revealing at once the highest joy and the deepest sadness," but focuses on the sadness:
They breathed the prayer and complaint of souls boiling over with the bitterest anguish. Every tone was a testimony against slavery, and a prayer to God for deliverance from chains.
He wonders how white people could think the songs showed the slaves were happy, saying they were a way to relieve the "sorrows of the heart" just as tears do.
Du Bois also describes the songs, which he knows of as someone who has always been free, as expressing the unhappiness of slavery:
They are the music of an unhappy people, of the children of disappointment; they tell of death and suffering and unvoiced longing toward a truer world, of misty wanderings and hidden ways.
Dubois speaks of the omissions of the songs: themes such as wooing and wedding do not appear because that was not part of the slaves' experience. He emphasizes a bit more fully than Douglass that these are songs of hope as well as despair:
Through all the sorrow of the Sorrow Songs there breathes a hope—a faith in the ultimate justice of things. The minor cadences of despair change often to triumph and calm confidence … the meaning is always clear: that sometime, somewhere, men will judge men by their souls and not by their skins.
Douglass and Du Bois agree as to the meaning of the songs. The songs have nothing to do with happiness, but everything to do with grief and hope. The two men differ in tone: Douglass can convey the immediacy of how he experienced these songs as a slave and the way they expressed his own grief. He can speak first-handedly of their value in allowing slaves to express an overflow of sadness.
Du Bois is more detached and scholarly in his analysis of these songs, viewing them from afar. He understands how they have been twisted since slave days by mockery in minstrel shows and sees them as relics of a lost time but also as artifacts that are a gift to the world as art. None of this detachment is available to Douglass.