Mozart's Twelfth Mass, K. Anh. 232 Mozart's Twelfth Mass, K. Anh. 232 Mozart's Twelfth Mass, once a top seller among the liturgical compositions published by Vincent Novello in the 19th century, is a work no longer attributed to Wolfgang Amadeus Mozart. Köchel rejected the attribution to Mozart in the Anhang (appendix) of the first edition of his catalogue of Mozart's works, there listed as K. Anh. 232, and in later editions as K. Anh. C1.04. The mass was published in 1819 as No. 12 in Novello's series of masses by Mozart, which is the origin of its name. Simrock was the first to publish the mass
Catalogues of Beethoven compositions and Hans Halm published a catalogue of Beethoven's works, in which they assigned numbers to 205 "Werke ohne Opuszahl" (meaning "works without opus number" in German) to "some" of Beethoven's unpublished works. These numbers given these works are generally preceded by "WoO". The Kinsky–Halm catalogue also lists 18 works in an appendix as being either doubtfully attributed, or simply spurious. Some of those listed as doubtful have since been shown to be authored by Beethoven. These numbers are generally preceded by "Anh.", short for German "Anhang", meaning "appendix". The Swiss composer and musicologist Willy Hess also researched and published a