Unfinished work, on the theme of "O filii et filiae". The period of composition is established after Saint-Saëns' tenure at the organ of St Merry. The work is written for the horn newly invented by the dedicatee that featured an ascendant 3rd valve. A note is handwritten on the top of the manuscript by editor Auguste Durand: "Inachevé, composé pour Mr Halary // et exécuté à l’orgue de S. Merry par l’auteur" (Unfinished, composed for Mr Halary // and executed at the organ of S. Merry by the composer).