In our horn repertoire class at ASU we arrived recently at the topic of Beethoven 9. The fourth horn solo has been the subject of much speculation over the years. Some of the wildest speculation is on the topic of could it possibly have been written for the valved horn? The invention of the valve having been first publicly been noted in 1814, just ten years before the premiere of Beethoven 9.
An article on the topic of the fourth horn part of Beethoven 9 has been for some years over on my Horn Articles Online site, based on a portion of an article that was published in The Horn Call Annual 8 (1996). A good example of one of the root sources for the speculation that Beethoven 9 could have been valved horn is this quote from Richard Hofmann (1844-1918) from his book Praktische Instrumentationslehre [Practical Instrumentation] of 1893. Of this solo Hofmann wrote,
Until recently it was understood that Beethoven had only made use of wald-horns [natural horns]–(without ventils [valves]); but this cannot have been the case, for we find (1) the low G (not playable on the wald-horn); (2) Beethoven never used long successions of tones in a key with many sharps or flats as the signature. Oral tradition has it that at the time of Beethoven, Levi a fourth-horn player in Vienna possessed a recently discovered ventil-horn; on the ground of this discovery it was imagined that all horn passages could be played with equal quality of tone. Probably for this reason Beethoven (who could scarcely have heard it himself in his greater and later works) wrote the difficult passage for the 4th horn in E-flat. The whole part lies badly for the player, and in view of the tone there seems no doubt that the second half of the solo is better on an E-horn.
Before going any further, Hofmann is wrong! The solo is very playable on the natural horn. It is not even that hard. If you read on in Hofmann he additionally notes how the solo could be divided between two players, the first seven bars being performed as written and the conclusion performed on the E crook; presumably implying that an early player might have done that same thing to play the solo by changing valves on a valved horn. The late Louis Stout also presented this idea in his The Horn: From the Forest to the Concert Hall video, so this idea is for sure still bouncing around out there in the horn world.
Again, the short version is Hofmann is incorrect; he did not understand the natural horn but Beethoven did. The part is a natural horn part. I cover a number of angles on this in my longer article but this is the essential one, quoting myself from 1996:
There is nothing in this solo which exceeds the technical demands which could be reasonably requested of a skilled performer of the natural horn. For comparison, the difficult written A-flat major scale is given in several exercises in the Domnich Méthode, and the low written G1 is seen in several other period works, including Beethoven’s own Horn Sonata, Op. 17, written early in his career for the virtuoso Punto. While not a true harmonic available on the horn, it was a “factitious” tone certainly well known among hornists and possessed a clear tonal color. While one could perhaps argue that the solo might sound better on the valved horn, the fact is that this is idiomatic, if virtuostic, low horn writing for the natural horn and well within the bounds of the technique of a conservatory-trained natural hornist….
Putting it another way, any player who has worked through a good portion of any classic natural horn method successfully with a good teacher should be able to play the Beethoven 9 solo. Imagine if natural horn was all you had ever played and you were proficient enough to be a leading player in a major metropolitan area of the day? The Beethoven 9 solo might be a surprise as it showed up on your stand, but if you had worked on pieces such as the Weber Concertino and warmed up on your scales and arpeggios daily really it would not have been a problem to play this on natural horn. There should be no controversy on that point. Check my full article for more.
UPDATE: See also this Horn Call article by Theodore Albrecht, “E.C. Lewy and Beethoven’s Ninth Symphony Premiere,” for even more on the topic.