Franz Xaver Süssmayr (German: Franz Xaver Süßmayr or Suessmayr in English; 1766 – September 17, 1803) was an Austrian composer and conductor. Popular in his day, he is now known primarily as the composer who completed
Wolfgang Amadeus Mozart's unfinished Requiem. In addition, there have been performances of Süssmayr's operas at Kremsmünster, and his secular political cantata (1796), Der Retter in Gefahr, SmWV 302, received its first full performance in over 200 years in June 2012 in a new edition by Mark Nabholz, conducted by Terrence Stoneberg. There are also CD recordings of his unfinished clarinet concerto (completed by Michael Freyhan), one of his German requiems, and his Missa Solemnis in D.
Of special note may be the clarinet concerto (SmWV 501) he most probably wrote for Mozart's clarinetist
Anton Stadler, because it was scored for the basset clarinet. Recordings of the work by Dieter Klöcker (on Novalis) on "normal clarinet" and by Thea King (on Hyperion) in a reconstructed version for basset clarinet by Michael Freyhan are available.
