Haydn and Mozart both wrote concertos for the French horn. Haydn wrote his for players in his orchestra – Thaddaus Steinmüller (first horn) making more use of upper register, and Carl Franz (second horn), making less use of higher registers, though he was also excellent at the higher pitch. Mozart wrote his horn concertos for his friend Joseph Leutgeb, the manuscripts being covered in jokes and, in one case, using different colours of ink.
But Haydn and Mozart were not writing these concertos in a vacuum. Many more horn concertos were written in those days than later – not what you might expect, since they were composed for the natural horn rather than the valve horn we have now. It took a great deal of technique to play these works using a natural horn, mainly involving use of the hand in the bell of the instrument.
This post concerns two composers of the time. They both composed many works for the French horn and both died not long after Mozart.
Franz Anton Rösler (c1750-1792)
Rösler wrote 16 concertos for horn and orchestra and 7 concertos for two horns and orchestra, one of which is lost. He died the year after Mozart, but not before composing a requiem for him. Their composing careers covered the same period.
Rösler changed his name to Francesco Antonio Rosetti. Since there is reason to believe he never set foot in Italy, my guess is that he used the change of name for marketing purposes. (The conductor Sir Adrian Boult once quipped that his profile would have been higher had he been called Adriano Bolto.)
František Xaver Pokorný (1729-1794)
The name Pokorný means ‘humble’ in Czech, the surname is common, and correctly attributing works to this composer is something of a minefield since he was not the only composer of this name. To make matters worse, after his death his surname was erased from many of his works and replaced by the names of other composers by the intendant of the Regensburg orchestra, Theodor von Schacht. (Wikipedia) It is clear, however, that he was a prolific composer who wrote concertos both for solo horn and two horns.
Why would he do this? One reason may have been Beate Pokorný, a horn virtuosa who was very popular in the Paris Concerts Spirituels of the 1780s. According to http://www.allmusic.com she ‘was not Pokorny’s daughter, but may have been his sister.’ A presenter on BBC Radio 3 was recently of this view. (Either that or his researcher was.)
Whatever their relationship, it is good see a lady horn player achieving such distinction at any time.
The Haydn scholar H C Robbins Landon has suggested that Mozart may have been influenced by Rösler’s concertos. It is not known if Mozart heard any of them, but an advanced interest in the horn is clearly evident as early as the Divertimento K.131, which contains an amazing passage for four horns. It was written in 1772 when Mozart was 16. As Erik Smith points out (Mozart Serenades, Divertimenti and Dances) this passage ‘remained unique for half a century or more’.