‘When you’re not offensive in life, you obtain absolutely nothing,’ declares a twinkly-eyed Pierre Boulez in one of the archive films that the Barbican were screening to celebrate the composer’s centenary. What a joy to be reminded of the young Boulez – the unashamed elitist, the unbeatable snob. Not even allies such as Schoenberg (too trad) and Messiaen (‘vulgar’) were safe from his tongue.