Offertoires IX "La St. Cécile" (incomplete) and XI (unknown, last page only), from "XII Offertoires pour l'Orgue" - Paris, 1766.
Offertoire IX (0.00 - 1.25)
Offertoire XI (1.30 - 2.54)
Michel Corrette (10 April 1707 – 21 January 1795) was a french organist, composer and author of musical method books.
Corrette was born in Rouen, Normandy. His father, Gaspard Corrette, was an organist and composer. Corrette served as organist at the Jesuit College in Paris from about 1737 to 1780. It is also known that he traveled to England before 1773. In 1780 he was appointed organist to the Duke of Angoulême and some 15 years later died in Paris at the age of 87.
(from Volume edit by L.E.O. 2012-France) - "In that unique copy, pages 27-30 are missing; so, Offertoire IX. La Ste Cécile is incomplete (1st page only), Offertoire X. is missing completely, and Offertoire XI. has the last page only".
http://hz.imslp.info/files/imglnks/usimg/0/0a/IMSLP308551-PMLP331320-Corrette_Offertoires_09.pdf
http://imslp.nl/imglnks/usimg/b/bf/IMSLP308553-PMLP331320-Corrette_Offertoires_11.pdf