Conversation so far:
What does St. Francis have to do with Olivier Messiaen?
Saint François d'Assise is an opera in three acts and eight scenes by French composer and librettist Olivier Messiaen, written from 1975 to 1983.
What was the piece Olivier Messiaen composed with St. Francis?
Saint François d'Assise is an opera in three acts and eight scenes by French composer and librettist Olivier Messiaen, written from 1975 to 1983.
What are the canyons mentioned in the Olivier Messiaen article?
Olivier Messiaen arranged a visit to the US in spring 1972, and was inspired by Bryce Canyon in Utah.
How did the canyons in Utah influence Olivier Messiaen's work?
Olivier Messiaen was inspired by the birds and the landscape.
What does transfiguration have to do with Olivier Messiaen?
La Transfiguration de Notre Seigneur Jésus-Christ by Olivier Messiaen. It is based on the account found in the synoptic gospels of Jesus' transfiguration.

Question: what was significant about that work?
Self-contained rewrite: What was significant about Olivier Messiaen's work La Transfiguration de Notre Seigneur Jésus-Christ?