Beethoven’s “Diabelli Variations”, written between 1819 and 1823, mark the pinnacle of his oeuvre for variations and next to Bach’s “Goldberg Variations” form one of the most important contributions to this genre. In addition to Beethoven, 50 other composers from Austria, mainly Vienna, followed Diabelli’s call to create variations for his famous waltz, among them Czerny, Moscheles, Fr. X. Mozart, Schubert, the 11-year-old Liszt and J. N. Hummel. The variations first printed by Diabelli fictively as “Fatherlandish Union of Artists Part I” (Beethoven’s op. 120) and “Part II” (the 50 variations of Vienna’s “most excellent composers and virtuosos”) are presented here by Mario Aschauer for the first time in one edition. Furthermore the variations of Part II appear in an Urtext edition for the first time. The musical text is based on a meticulous study of the sources and for the first time relevant discrepancies between the main sources are presented in light grey print. A detailed Critical Commentary (Eng) and notes regarding Viennese piano performance practice during Beethoven’s day complete this special Urtext edition based on the most current research.