The so-called Violin Concerto No. 7 in D major, K. 271a/271i, may have been completed by Wolfgang Amadeus Mozart on 16 July 1777 in Salzburg. It has been called the Kolb Concerto. Structure The concerto has the usual fast-slow-fast structure and lasts around 26 minutes. The movements are: Background This violin concerto was first published by Breitkopf & Härtel in an edition by Albert Kopfermann in 1907. Two sources are known for the concerto: a full score from the collection of Aloys Fuchs and a set of parts in Paris made by Eugène Sauzay in 1837 for his teacher (and also father-in-law) Pierre Baillot from the lost autograph (then in the possession of François Habeneck). The source of Fuchs' copy is unknown, and he himself was not sure of the work's authenticity: its layout with the solo violin part on the bottom staff is very uncharacteristic of Mozart, where the solo instrument is usually on the top staff. However, a paper scrap in Sauzay's copy lists the instruments in exactly the same order and the same horn solmisation found in Mozart's authentic violin concerti, supporting the work's authenticity: this was noted by Robert D. Levin. As to how the autograph (if it was truly that) ended up in Habeneck's possession, Mozart may have sold the autograph privately in Paris and the husband of Sauzay's friend Marie Bigot de Moragues had connections to Viennese music publishers. Three cadenzas are found in the Paris copy; two may be Baillot's and the third Sauzay's. Fuchs' copy also had different cadenzas, which Kopfermann suppressed, considering them inauthentic. The two copies differ in some places, and a 37-bar ending in Fuchs' copy corresponds to a short 7-bar ending in the Paris copy: this is seen by some to correspond to Mozart's 1778 statement "If I have time, I shall rearrange some of my violin concertos, and shorten them". The concerto was unknown to Ludwig Ritter von Köchel and hence it is absent from the first edition of the Köchel catalogue. Paul von Waldersee placed it as K. 271a in the second edition, dating it to 16 July 1777. It was first performed on 4 November 1907 in Dresden. After its first publication and performance, scholars took sides regarding its authenticity. Georges de Saint-Foix did not doubt the work, but believed the published version was a later revision by Mozart dating to 1779 or 1780. Others