Auden, who wrote many different forms of poetry, here blends two traditions—the nursery-rhyme lullaby and the carpe diem motif. Since the poem begins by addressing an adult lover, not a child as is usual in a lullaby, it is a nontraditional form of the lullaby. Yet the poem is also very musical; it ends by being soothing and wishing eternal love for the lover just as a parent might wish for eternal happiness for an innocent child in a traditional lullaby.

Auden also includes variations of the carpe diem theme in this lyric. In a traditional carpe diem poem, such as Andrew Marvell’s “To His Coy Mistress,” a male speaker, usually promising undying devotion and love, tries to persuade a reluctant or coy female beloved to make love to him now while they are still young and passionate rather than old and gray. He claims if they love each other they are, in a way, “married” and should consummate their passion. In “Lullaby,” the gender of the beloved is ambiguous; since Auden was homosexual, both lover and beloved could be males. The speaker in “Lullaby,” instead of promising eternal love, says that his arm is “faithless” and questions the whole notion of fidelity. Most carpe diem poems are attempts to establish a carnal affair, but Auden’s poem seems to be set after the lovers have made love—a kind of post-coitus meditation. In both traditional carpe diem poems and Auden’s “Lullaby,” passionate love is primary and necessary. The goal of this poem and of more traditional carpe diem poems is to preserve a fleeting moment of carnal ecstasy and intense beauty and thereby temporarily to defeat time. In “Lullaby,” therefore, Auden playfully and artistically weaves together nontraditional elements from both the carpe diem and lullaby traditions to create his own new hybrid form of poetry.

“Lullaby” also is about the power of poetry to accomplish the impossible—to freeze time temporarily. To make a magical night of love immortal and timeless, the poet writes a poem about it that captures the contrary pulls between passion, beauty, time, and human awareness of all three and relays it to readers in the present tense. By writing the poem, Auden attempts to preserve the feelings and attitudes evoked by one of the most powerful emotions humans ever experience: passionate love.