Missa solemnis (Beethoven) From Wikipedia, the free encyclopedia ‹ The template Infobox musical composition is being considered for merging. › Missa solemnisKeyCatalogueTextDedicationPerformedScoring by Ludwig van Beethoven In this famous portrait of Beethoven by Joseph Karl Stieler, Beethoven can be seen working on the Missa solemnis. D major Op. 123 Order of Mass Rudolf of Austria 7 April 1824..