Julianne Moore could put a toothpaste advert into awards contention with the inner turmoil she conveys with her magnificent eyes. She certainly lifts her scenes in this slushy, heavy on the romance adaptation of Ann Pratchett’s novel about a world-famous opera singer falling in love with a Japanese billionaire during a hostage crisis. If the book is a work of elegant literary fiction, here we have the movie equivalent of a bumper airport paperback: always watchable and often soapy, with a handful of unintentional giggly bits.

Moore is Roxanne Coss, an American lyric soprano paid silly money by the government of a nameless Latin American country to perform at a soiree to impress electronics boss Mr Hosokawa (Ken Watanabe). When leftist guerrillas waving machine guns storm the party, their target is the country’s president, but he stayed home to watch his favourite TV soap opera so the hijackers take the guests hostage instead.

Inevitably, there is a moment when Moore opens her mouth to sing and you think: is the lip-syncing going to be terrible? Actually, no. Moore turns the diva level to low with her understated performance; Roxanne has star presence and a degree of celebrity entitlement but she’s not rude. Moore even manages a straight face in scenes demonstrating the power of art – Roxanne’s soaring voice melting everyone into puddles on the floor. Look! Even the soldiers are weeping.

As stalemate negotiations drag, terror gives way to boredom. Roxanne and Mr Hosokawa flirt. The hostages and kidnappers make connections, like a two-way Stockholm syndrome; the French ambassador takes a boy-soldier under his wing – the kid reminds him of his son at 16. There’s chess, singing lessons, football and stolen kisses in the laundry cupboard. It’s overripe and improbable, but you’d need a flinty heart to resist the message of solidarity, that if you spend time with someone, anyone, you’ll find common ground.