An excuse first. This can only be a magpie’s look at a marriage – between poetry and music – that has a near-infinite history of complex living arrangements, recurrent divorces, remarriages and impromptu de facto cohabitations. I’ve chosen a few marital battles of particular interest to me, a writer for whom song is a sometime thing. I’d like to claim those battles as representative of some epochs and musical styles, at least within various Western traditions; they are certainly representative of my musical obsessions.

The first of these obsessions is this: why music? Most writers, especially most poets, tend to think that words are enough music in themselves. Words don’t need musical backings, or settings, or singings. To flog the metaphor: why get married to a composer at all? Oscar Hammerstein II wrote the lyrics for Jerome Kern’s musical Showboat. Mrs Oscar Hammerstein, so the story goes, once overheard someone praise ‘Ol’ Man River’ as a ‘great Kern Song’. ‘I beg your pardon,’ she interrupted, ‘but Jerome Kern did not write “Ol’ Man River”. Mr Kern wrote dum dum dum da. My husband wrote Ol’Man River.’

So, mine will be a biased, poet’s eye view of the relationship. My starting point again: why music? We all know ‘why’ language – because nothing much that is uniquely human happens without it. We can see why a capacity for language might evolve in our brains over a million years – its survival advantages are obvious – but why a capacity for music?