Violin Concerto No. 7 (Mozart) to the insertion of new works bearing the numbers K. 271b to K. 271H in the catalogue. He believed that the work was based on a rough sketch of a violin concerto by Mozart from 1777, but states that the original form of the work cannot easily be reconstructed. The uncharacteristic number of passages for the solo violin in the high register, in "pizzicato" (in the second movement), and in double stops in tenths were considered by Einstein to be 19th-century additions. Friedrich Blume, on the other hand, was firmly in favour of the work's authenticity, stating that "not one
Köchel catalogue three revised editions of the catalogue. Subsequent editions – especially the third edition (K) by Alfred Einstein (1937), and the sixth edition (K) by Franz Giegling, , and Alexander Weinmann (1964) – have reflected attempts to arrange the growing list of works in a more accurate chronological order, according to various levels of scholarship. A major shortcoming of K was that there was no room to expand the strictly sequential numbering in the main catalogue to allow for any new discoveries or further reassessment of existing works. For the 1937 edition (K) Einstein (following the analyses of Théodore de Wyzewa