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.". 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.