This is always done in the name of relevance, as though audiences could not possibly feel the moral or emotional force of anything set in the more distant past. Sometimes, of course, such a process can yield genuine illumination – Carrie Cracknell’s recent Wozzeck for ENO was very powerful, and even the most conservative opera-goer loves Jonathan Miller’s Wodehousian take on The Mikado – but too often it throws up confusions and contradictions which undermine credibility. Put Mimi in any post-war context and you can’t help wondering why she didn’t take advantage of free medical care, for example, while Le Nozze di Figaro doesn’t make sense later than Napoleon’s abolition of the droit du seigneur on which the plot is premised.