French composer Olivier Messiaen wrote his most famous piece, Quartet for the End of Time, from the prisoner of war camp where he was interned in 1940. A devout Catholic, Messiaen was a church organist, a Conservatoire teacher, and an ornithologist -- so his music is full of birdsong, modernism, and God. His peers accused him of mixing “the bidet with the baptismal font” (Poulenc), of writing “brothel music” (Boulez), and “sacroporn” (Richard Taruskin), but as Robert Sholl argues in his new critical biography, he was committed to “revealing his world”. Robert joins Andy to traverse the great distances of that world.