When John Ashbery was invited to deliver the Norton Lectures at Harvard in 1989, He declined to spell out what he put on the page. Instead, he offered rapt audiences a tour of his influences, the authors he turned to as a “jumpstart for times when the batteries have run down. To commemorate the centenary of Charles Eliot Norton Professorship in Poetry and its distinguished lecture series, Harvard University Press presents five landmark titles from the series, each reissued with a new foreword by a distinguished contemporary voice.