Léon Boëllmann (1862–1897) studied at the École Niedermeyer and was titular organist at St-Vincent-de-Paul in Paris. In the tradition of Saint-Saëns, Franck and Gigout, his compositions reflect the elegant urbanity of the Belle é poque.

Published in 1896, Heures mystiques is a collection of one-hundred short pieces for organ or harmonium offering organists a treasure-trove of easy compositions for use in church services. The appendix contains suggested alterations to the musical text as examples for imaginative renditions on multi-manual instruments.