In 1957, the biographer Leon Edel was passing through Montreal and decided to call on his old friend A. M. Klein. Then forty-eight, Klein had emerged from the immigrant streets of his “jargoning city” to become the most prodigious poet at work in Canada. Raised in a Yiddish-speaking household, he studied Hebrew, was educated in English, and learned French. (In one poem, Klein wrote that the ships docked at Montreal’s harbor unloaded not just cargo but “lexicons.”) He channeled that polyglot upbringing into English-language poems of uncommon fluency, an eloquence fueled by an endlessly self-replenishing gift for arresting phrases. Klein’s prose, with its improbable range, was no less remarkable. He reeled off plays, lectures, speeches, editorials, book reviews, short stories, and novellas. He even took a stab at a spy thriller. This rhetorical largesse echoed in his baritone delivery. A gifted orator, Klein could quiet a packed hall. His poetry readings had a declamatory flow that mesmerized. His was the voice of a man who wrote for sound as much as sense, a man obsessed with the musicality of words.

That man was nowhere to be found when Klein greeted Edel at the door. It had been decades since the two were undergraduates at McGill University, walking home together on winter evenings after class. As a student in the mid-1920s, Klein was driven, voluble, quick on the uptake. Two years his senior, Edel was awed by his friend’s precocity—Klein had appeared in Poetry magazine at the age of