Missa Cellensis in honorem Beatissimae Virginis Mariae

The Missa Cellensis in honorem Beatissimae Virginis Mariae in C major by Joseph Haydn, Hob. XXII:5, Novello 3, was originally written in 1766, after Haydn was promoted to Kapellmeister at Eszterháza following the death of Gregor Joseph Werner. The original title as it appears on the only surviving fragment of Haydn's autograph score, that has been discovered around 1970 in Budapest, clearly assigns the mass to the pilgrimage cult of Mariazell, Styria. Until that discovery, the work was known as Missa Sanctae Caeciliae, or in German Cäcilienmesse, a title probably attributed to the mass in the 19th century. Whether the alternative title refers to a performance of the piece by the St. Cecilia's Congregation, a Viennese musician's fraternity, on some St. Cecilia's day (22 November), as has been suggested, remains speculation.

It is believed that the original manuscript was lost in the Eisenstadt fire of 1768, and that when Haydn rewrote the piece from memory, he may also have expanded it. It may have originally consisted of only Kyrie and Gloria, with the other parts added later. This Mass was known to Anton Bruckner.