his Wind Octet, later published as Opus 103, and several sets of Variations, including one (WoO 40) for violin and piano on Mozart's aria "Se vuol ballare" (later reworked in Vienna). Although these works largely conform to the formal conventions of the classical style, including strict observance of form and, in the variations, the decorative filigree associated with the genre, they also show early signs of Beethoven's later tendency to the more substantive treatment of thematic material. Beethoven also produced numerous fragments of larger-scale works, including a symphonic movement (also written in C minor), a violin concerto, an oboe concerto, an early draft of his B-flat Piano concerto (both now vanished), and a concertante for piano, flute and bassoon. Scholars generally regard these early efforts as bland and uninspired and have concluded that his first efforts at writing in the classical sonata style (with the exception of his Wind Octet) were poorly conceived. Gustav Nottebohm, for example, wrote of Beethoven's Dressler Variations (WoO 63), "they show not a trace of contrapuntal independent part-writing. They are figural variations of the simplest kind". Téodor de Wyzewa considered his early "Kurfürsten Sonatas" written in 1783 (WoO 47) as merely "correct imitations of Haydn.". The most ambitious work that Beethoven composed during his Bonn years was a funeral cantata to commemorate the death of Emperor Joseph II, commissioned by the literary society of Bonn. Though it was not performed, it was evidently impressive enough that Beethoven was commissioned to write a second cantata ‘On the Accession of Leopold II to the Imperial Dignity’, which was again not performed. These works already show skill in choral writing, as well as in writing arias, the latter also exhibited by three concert arias he composed around this time. Considered as a whole, Beethoven's compositional efforts in Bonn demonstrate the importance of his move to Vienna in terms of the development of his musical style and the sophistication of his grasp of classical form and idiom, for his efforts in the sonata style are less accomplished than his efforts in other genres like variations, Lieder, and large vocal-orchestral pieces. Early Vienna Period For the first years after moving to Vienna, Beethoven composed considerably less than he did either before or after. Not only was he studying with Haydn and Albrechtsberger, but he was also revising several of his Bonn works to cater to Viennese styles and tastes. However