In the middle of last week’s Catholic People’s Week in the Lake District, a lay-organised gathering of talks, discussions and workshops, the Messiaen scholar Christopher Dingle had to lay aside playing bass guitar for the daily Masses to travel to London for the world premiere of a recently rediscovered piece by the composer at the Proms. Dingle, a professor of music at Birmingham Conservatoire, had realised the orchestration of Messiaen’s Un oiseau des arbres de Vie (oiseau T