Horn Concerto No. 1 (Mozart)

Wolfgang Amadeus Mozart's Horn Concerto No. 1 in D major, K. (412+514)/386b was written in 1791. The work is in two movements. Unusually, each movement received a distinct number in the first edition of the Köchel catalogue:
The concerto is scored for solo horn, two oboes, two bassoons, and strings. This is one of two horn concertos of Mozart to include bassoons (the other is K. 447), but in this one he "treats them indifferently in the first movement." It is the only one of Mozart's horn concertos to be in D major (the rest are in E-flat major) and the only one to have just two movements instead of the usual three (with the exception of the incompletely scored horn concerto, K. 370b+371).
Although numbered first, this was actually the last of the four to be completed. Compared to the other three horn concertos, it is shorter in duration (two movements rather than three) and is much simpler in regard to both range and technique, perhaps in a nod to the horn player (Mozart's great friend) Leutgeb's advanced age and (presumably) reduced capabilities at the time of composition. The second movement, K. 514, was shown by Alan Tyson to have been finished by Mozart's student Franz Xaver Süssmayr after Mozart's death.
Mozart's autograph score contains, arranged in strategic places throughout the sketch of the Rondo, a bizarre written narrative in Italian almost certainly directed to Leutgeb:
A comparison between Mozart's draft and Süssmayr's version reveals that Süssmayr used very little of Mozart's material: b.1–40 of Mozart's autograph corresponds almost exactly to b.1–44 of Süssmayr's version, and the two thereafter diverge with only a few passages in Süssmayr (b.59–62, 84–92, 109–116) bearing any close relationship to Mozart's material. Süssmayr's rondo also makes use of a plainchant melody (the "Lamentationes Ieremiae prophetae"), and one explanation of this is that the melody was copied out by Mozart while he was composing the Requiem, which Süssmayr later mistook as material for the rondo.
Discography.
Given its duration (no more than 10 minutes), the Concerto is typically grouped with Mozart's other 3 for the instrument. The foremost example is Dennis Brain's November, 1953 recording of the four horn concertos on EMI with The Philharmonia Orchestra, conducted by Herbert von Karajan.