What style is Messiaen?
For a short period Messiaen experimented with the parametrisation associated with "total serialism", in which field he is often cited as an innovator. His style absorbed many global musical influences such as Indonesian gamelan (tuned percussion often features prominently in his orchestral works).
Was Messiaen a Catholic?
Religion was considered the single greatest motivator for Messiaen's music, in his secular as well his many sacred compositions. He had vowed as a youth to make Roman Catholic dogma the basis of all his work. ... “My music was far below the violence of the psalms they were reading,” he said.