For more than a century, American poets have heeded the siren song of Ezra Pound's make it new, staking a claim for the next poem on the supposed obsolescence of the last. But great poems are forever rehearsing their own present, inviting readers into a nowness that makes itself new each time we read or reread them. They create the present moment as we enter it, their language relying on the long history of lyric poetry while at the same time...