It hardly needs saying: David Belasco’s 1905 play The Girl of the Golden West would be hooted off the stage these days, for its clichés, its gimcrack realism, its sentimentality, its tawdry domesticity, its sheer dumbness. Thus does theatre become redundant – or is it more to do with our superior attitude to our forefathers’ taste? In fact, Belasco was a sort of American Stanislavsky, and the inventor of a new kind of naturalistic theatre.That’s what grabbed Puccini, who did the same to opera. In the earlier La Bohème and Madama Butterfly, he found “big sorrows in little souls” to elevate to the epic. His 1910 opera La Fanciulla del West has never been as popular – the sorrows are smaller and the setting is too corny – but in p