My two attempts to see Poulenc’s Dialogues des Carmélites at the Guildhall School were frustrated by the weather. Forced back on to my DVDs and CDs — vinyl, even — I took the opportunity to survey some of the manifestations and investigations of religious feeling in 20th-century French music.

I began with Vincent d’Indy’s Fervaal, an opera he composed in 1895 which used to be referred to as ‘the French Parsifal’.