It is called An American in Paris, but perhaps a more apt title would be The Americans in Paris. Not because the story is about two ex-servicemen who decide to ditch the victory parades back home and stay in a recently occupied city that is in desperate need of revival; but because the show itself is a triumph of the American musical as an art form, a kind of staking out of territory. It is, in its own way, an act of cultural imperialism, a banishment of old conventions in favour of something shiny and new. Proof of this comes deep into the second act, when a French character who fancies himself ‘a song and dance man’ suddenly launches into a fully fledged tap routine that ends with a high-kicking chorus line straight out of Radio City Music Hall. We are still in Paris, right?