Half a century ago and more, C.S. Lewis gave a conference paper on English metre in the Holywell music room in Oxford, where the great composer Handel was once thought to have performed.

The Handel myth is no longer credited, if only because in 1733, when he visited Oxford, the room had not yet been built. In any case Lewis's performance was neither harmonious nor meant to be. He was addressing an audience of university teachers of English and reproaching them for not teaching metre; and his solution was hard to swallow. The mysteries of English metre can only be explained, he suggested, on the assumption that readers carry metrical paradigms in their brains like invisible iPods: an inner metronome ticks as you read a poem, contrasting what you hear in the mind with what you take from the page. The audience looked sceptical and said little. The paper appeared in 1960, three years before Lewis's death, and was collected in his Selected Literary Essays in 1969. I have not heard anyone speak of it lately, and the name of C.S. Lewis survives mainly as the author of the Narnia stories and in plays and films about his late marriage to a New Yorker. Metre is discussed, if at all, by those who write poetry, not by those who read it.

The audience looked sceptical for more reasons than one. It seemed incredible to suppose that a reader could recall a metre that was not there, and ...