With its end rhymes, rhythms and references to choirs and bells, this poem is downright musical. And that's as it should be, right? After all, it's called an "Anthem" for a reason. And while we can't tell you why Owen wrote the way he did (maybe he just thought it sounded nice) we can talk about the effects that it has. Among the most significant, in our book, is the way that the beautiful, musical language contrasts with the terrible sounds and images of war and death.
Why do we think that's so great and significant? Well, it matches pretty well with what our speaker does in the poem: that is, contrasting the holy rituals that mark death in the civilian world with the ugly realities of dying on a battlefield. Take lines 2 through 4, for example:
Only the monstrous anger of the guns.
Only the stuttering rifles' rapid rattle
Can patter out their hasty orisons. (2-4)
There's an almost chant-like repetition at the beginning of lines 2 and 3. There's all those "r" sounds, bouncing off the consonance of those "t" sounds. There's the full rhyme of "guns" and "orisons." It's musical and exciting and yet "monstrous" and frightening. It's rousing, but at the same time we recoil from it. The poem mimics the way that talk of courage and fighting for God and glory (and all the pomp and circumstance that follows the last full measure of devotion) acts as a disguise for the senselessness and suffering of war. Only, through words like "monstrous," the poem makes sure that we're well aware of the dissonance.