he whistles his Jews into rows has them shovel a grave in the ground he orders us strike up and play for the dance (lines 9-10)
The Jews could either be shoveling graves for themselves or for others in the camp who have died recently. Either way, they are confronted with the possibility of death at any moment, which is part of the idea behind the whole "we're drinking black milk at all hours" thing. As if that weren't bad enough, the guard forces some of the Jews to play a "Deathfugue" or "Death Tango."
he writes when it grows dark to Deutschland your golden hair Margeurite your ashen hair Shulamith we shovel a grave in the air there you won't lie too cramped (lines 15-16)
Shulamith's "ashen" hair reminds us of smoke and the "grave in air" that is mentioned throughout the poem. The bodies of Jews in the Holocaust were often burned in crematoriums, and they were denied graves and the religious rites of a funeral. A mysterious voice within the poem tries to make up for this loss by offering the thought that "there you won't lie too cramped." Whose voice is this?
He shouts play death more sweetly Death is a master from Deutschland he shouts scrape your strings darker you'll rise then in smoke to the sky you'll have a grave then in the clouds there you won't lie too cramped (lines 25-27)
Death is everywhere in this poem, isn't it? First, "death" is the name of the song the Jews are playing, and which the guard cruelly wants them to play "more sweetly." Second, death is "a master from Deutschland." It's as if death itself has taken over Germany and is running the country. Finally, it seems that the guard might have been that mysterious voice luring the Jews toward a "grave […] in the clouds."
Black milk of daybreak we drink you at night we drink you at midday Death is a master aus Deutschland we drink you at evening and morning we drink and we drink (lines 28-30)
In the final turn of the fugue, did you notice how Celan slipped "Death is a master aus Deutschland" into the theme about black milk? This addition makes the poem seem to move faster and more out of control, and it also foreshadows the depiction of executions in the last stanza.
he shoots you with shot made of lead shoots you level and true a man lives in the house your goldenes Haar Margarete he looses his hounds on us grants us a grave in the air (lines 32-34)
This description of executions is chillingly matter-of-fact. The prisoners did not have any chance of escape; the guard merely points and shoots. But beneath this orderly facade, you can only imagine the panic and terror of the scene. Why does Celan choose to understate this last bit?