W. H. Auden was a ruthless editor of his own poetry, who in later life suppressed many early poems he no longer found worthy. He took an even more pitiless attitude towards his texts for opera, though he expected others to do the pruning. The verses of a libretto, he wrote, "have their moment of glory, the moment when they suggest to [the composer] a certain melody. Once that is over, they are as expendable as infantry to a Chinese general: they must efface themselves and cease to ...