Jewels brought from bondage
Gilroy uses the imagery "jewels brought from bondage," in order to describe black music. This is an interesting use of imagery and is an allusion to the artistic beauty that can arise from terrible suffering. Here, he is speaking specifically about the slave trade, which is described as "bondage" here.
Music
Quoting a poem by James Weldon Johnson, Gilroy uses the imagery of this poem to illustrate his ideas about black music. The poem begins with the following stanza:
"O black and unknown bards of long ago,
How came your lips to touch the sacred fire?
How in your darkness, did you come to know
The power and beauty of the minstrel's lyre?"
Here, Johnson uses a number of different references to imagery, including the "sacred fire" of artistic creation and the "darkness" of ignorance and suffering.
The imagery of double consciousness
At the beginning of the text, Gilroy introduces his theory of "double consciousness." He describes how "all blacks in the West... stand between (at least) two great cultural assemblages." Here, this imagery is used to express the complex nature of black identity.
