The two-movement, incompletely transmitted Horn Concerto in D major K. 412 was long considered as Mozart s first horn concerto - it is, however, his last, and was written between March and December 1791. Mozart undertook revisions in the autograph which contains the most important orchestral parts next to the entire solo horn part in order to adjust the work to the modest technical abilities of the planned soloist Joseph Leutgeb. Mozart revised and completed the first movement, eliminated lower notes in the solo part, rewrote difficult passages and expanded orchestral interludes to give Leutgeb additional breath rests. Mozart also made similar simplifications in the second movement as well, but his early death prevented the completion of the work.Robert D. Levin reconstructed both versions of the concerto on the basis of the autograph. Next to the version revised by Mozart ( post correcturam ), he now presents the original version ( ante correcturam ) for the first time in a musical text revised and supplemented according to rigorous philological criteria. / Conducteur