‘Hi, it’s Jonas.’ When the great tenor rings from Vienna, I ask if there are any topics he wants me to avoid, such are his minders’ anxieties. ‘Ask anything,’ laughs Jonas. ‘I’m not shy.’

He is heading in from the airport to see a physio — ‘these concerts, you have to stand there all the time’ — before taking Hugo Wolf’s Italian Songbook on a seven-city Baedeker tour: Vienna, Paris, London, Essen, Luxemburg, Budapest, Barcelona.