Swinburne opens with a complaint that sounds almost like etiquette. Death and birth, he says, "should dwell not near together," as if they were ill-assorted neighbours. He backs this up with a social comparison: wealth does not keep house with dearth, "even for shame." The tone is bitter. Wealth at least has the decency to keep away from poverty, but fate has no manners and ties the start of life to its end in "one brief tether." The word "brief" does a lot of work. The tether is a human lifetime, and it is short.
That tether is the first of several images of harness. Death and birth are held by a "yoke" and a "girth," the strap that holds a saddle on a horse, and the poem plays on its own vocabulary when it says the girth "girds them each with each." We picture animals forced to pull together whether they like it or not. The second stanza is tight and harsh until its last line, where the voice turns and asks the question the poem has been circling: "yet whether / Death be best, who knows, or life on earth?" Until now the speaker has been certain that the pairing is wrong. Now he admits he cannot say which of the two is the better thing. That admission quietly undermines the complaint, because if you cannot tell whether death or life is preferable, it is harder to insist they be kept apart.
The third stanza moves from harness to ornament and weather. The "rose-red and the sable feather" sit together in "one crown's plume." Rose-red suggests flush, celebration and living colour, and sable, a word for black, suggests mourning (black plumes are a familiar funeral image). Then come "grief" and "mirth," and finally "warm and wintry weather." The comparisons keep widening, from a house to a harness to a crown to the seasons themselves. The last one is the most interesting, and here I am offering my own reading. Warm and wintry weather really do meet, in every spring and autumn, and nobody calls that a scandal. The poem's final image may undercut its own argument, as if the speaker half-knows that this mixing is simply how the world works.
The form adds to this. The poem is a roundel, a form Swinburne is well known for using in English. The refrain "Death and birth" opens the first line, stands alone as line 4, and closes the poem. The rhyme scheme is abaB, bab, abaB, so the refrain rhymes with "dearth," "girth," "earth" and "mirth." Every one of those words ends in the same breathy "th," and "death" itself shares the sound. The poem argues that death and birth should not be linked, but the form links them. The refrain is bolted to the end of each stanza, and the rhymes chain the two words to a whole family of related sounds.
The rhythm helps the effect. The long lines have a falling, trochaic lilt, with stresses on "DEATH," "BIRTH," "DWELL," "NEAR." The "a" rhymes are double: "together," "tether," "whether," "feather," "weather." Their soft two-syllable endings keep the lines swinging forward. Then the refrain arrives in three syllables, two of them heavy, and it lands like a lid closing. The middle stanza has no refrain at all. It is the one place where the poem loosens its grip, and it is also where the speaker says "who knows." Its last phrase, "life on earth," matches "death and birth" in rhythm and rhyme without repeating it, so the refrain's sound lingers even when the words are absent.
What makes the poem worth reading is how much it fits into eleven short lines. Its argument is simple, that opposites should stay apart, but it is built so that the structure contradicts the argument. The "ill met" pair cannot be separated because the poem keeps returning to them. It never settles whether death or life is the better thing. It ends on the refrain, with the two words tied together once more.