With all the background research, and knowledge that I presented leads us to 1848 which is an important date if we are talking about Schumann’s compositions and about the history of the horn. After Richard Wagner, Robert Schumann was the first major German composer, who gave a chance for the valve horn.  It went so well, that right after that he started to use it in 1848, he wrote two of the most famous, greatest and important pieces of the horn repertoire at the beginning of the next year. In February 1849, Julius Schlitterlau, who was the third horsnist in the Dresdner Staatskapelle, played the Adagio und Allegro with Clara Schumann together at the componist’s place.1 As many publishers, 2 3 and researchers 4 quote, Clara said the following about this piece: ‘The piece is magnificent, fresh and impassioned, just as I like it!’ 5
In the same month, within four weeks, between 18 February and 11 March, he already composed his other important piece for horn, the Konzertstück für 4 Hörner und Orchester op.86. No doubt, that both pieces are masterwork and since their premier they are one of the most beloved and famous pieces for horn. 

Why is this really interesting and unusual? Because composers usually learn how the instrument works, they try it out in different combinations, specially if it is a new instrument, but Schumann has only a couple of orchestral works, Manfred op.115, Adventlied für Sopran-Solo und Chor mit Orchesterbegleitung op.71, where he involved the valve horn, before he wrote these two amazing pieces. As I already said, it is not questionable that he could use the full potential of the Ventilhorn, and therefore it gets even more interesting why he did not forget the natural horn afterwards, and why did he still use it in his orchestral works, whether we take the symphony nr.3 or nr.4 (originally the 2nd), or his only opera, the Genoveva. It is clear that the main horn was the valve horn for him, since in the pieces where he uses only two horns, he always asks for the Ventilhorn, and the Waldhörner appear only in the compositions with two pairs of horns. As I asked in the introduction, why did he use this imperfect and ‘old’ instrument beside the new, perfect, and more complete version of the same instrument? 

With the background research, I tried to get to know this periode, what kind of role the horn had at this transformation phase and to see how the contemporary musicians treated it. It became clear that the German hornists were familiar with the new instrument, they did not abandon it, and they used it every day, but they did not forget the origin of the instrument, and it was important for them to know where the character of the horn come from, what was the reason to become one of the most beloved instrument. Although Wagner used the two instruments at the same time, in my opinion, Schumann was the greatest master of mixing the old and the new. As we see in the Adagio und Allegro op.70 and in the Konzertstück op.86, he knew what is possible on the valve horn, what is that new level what can be played with the valves, and even though, he kept the natural horn and was able to make more colourful his compositions.

 

Beside these techniques, Schumann used the horns just as almost every classical, early romantic composer. Mainly low crooks, to have the mellow and round sound of the instrument, and he asked for the higher keys only on a couple of special occasions. He never uses high horns in slow movements, and even the most chromatic parts do not step out of the circle of the usually used modified  notes.

This type of writing was already known by the classical composers, and they splitted the horn section into two groups, even when they used only two horns. For instance, Mozart in the Symphony in G minor Nr.40 KV.550, from bar 155-161, the first horn has the melody in the whole time, except bar 157 where it should play a closed and weak a’, but this is an open c” for the second horn, which plays in G, and with this solution that passage sounds also completely open and as one open instrument, like a trombone, which would have been the perfect instrument for this few bars, but since the composer did not need it in the rest of the piece, it would not have made sense to use an instrument only for 6 bars.

 

We can also see that he already tried to use the whole horn section as one instrument. In the bar before Allegro molto vivace in the first movement of the first symphony, all the horns play the same notes, but the 3rd and 4th horns (in Bb-basso)  have two stopped notes, F” and Bb, but this is not a problem, because they are do not need so much stopping, and the other two horns (in F) play the same at the same time.
Also a couple of bars later, the final chord, he uses the effect of the stopped notes. The second horn plays a closed A’, but this note is the third in the chord, therefore it is actually useful that it does not sound so open and loud, but more hidden and softer:

 

It looks like the 4th horn plays the same as the 1st horn, but actually it continues the melody with the next third step. As it is visible on the next picture, the last two bars would be too low for the Horn in A, therefore two out of the three notes would be stopped notes and hardly audible. Although the entire melody is doable and audible on the D-crook, the colour of the sound would not be the same. Immediately, the first note, sounding g’ would be a closed f” on the D-Horn, which makes it difficult to produce an open, and bright sound, and then hide the difference between this note and the two following notes that are open notes.

 

In longer melodies or motives, where it is modulating, he shared the melody between the differently pitched horns:

In order to study his writing in the late (after 1848) compositions, I was studying the earlier pieces as well, and here, the horn did not have any new role than in the previous era. Of course, it was more usual for him too, to use two pairs of horns, and both of them were tuned differently, mostly the tonic and the dominant key, but the horn still had the accompaniment role, they supported and gave extra sound colour to the melodies; and when accidentally they had a solo or soli, the used notes were part of the actual natural tone selection, just like in these few bars in the 4th movement from the 1st Symphony:

The horn parts in Schumann's early orchestral works