A recent master class with Javier Bonet at ASU brought up some great topics in relation to Mozart 3, with the following two main points to consider strongly.
There is an edition that many students in the USA use, the original Schirmer edition. They use it because it contains all four concertos and the concert rondo with music in F – and it is very inexpensive as well. What a deal!
Of course, Mozart put few expressive marks in the score (almost all of them in the typical edition are editorial), and you can sound good playing from any edition. However, this really is not a very good edition, the dynamics are so low, etc. If you want to step things up you need to get a better one. Playing from any edition with an Eb part is a step in the right direction, but you really should be using a recent edition such as for example the newer Schirmer (Tuckwell). Myself, I am partial to the Baumann edition (McCoy’s Horn Library), presently available only as a digital download.
Don’t sound boring
This is the other big point and one that horn students really need to take to heart. By himself, demonstrating in the master class situation, Bonet might sound a bit over the top in terms of dynamics and articulations. However, he is gearing his playing to being a soloist and a performer in large venues with audiences who pay money to hear him. In addition, if you listen to his recording of the Mozart concertos, the final product is expressive and refined.
In terms of auditions, another point I have heard made is that you want to have a “signature interpretation” of your solos. Stated another way, you do not want to sound average. One sure fire way to sound average is to play everything MP with very gentle articulations. Aim for long, beautiful phrases that have destination points played to a level they are easily audible. Use different articulations to accent certain phrases and ideas.
One point Bonet made related to the natural horn and going for more of a hunting horn sound on this. I would elaborate that there are a couple ways to approach the natural horn. One way would be seen in something like the Gallay unmeasured preludes, of which I wrote recently (here). These “small room” works cry for an intimate and expressive approach. Then we have Mozart concertos; these are for larger venues with soloists playing (with an orchestra) to audiences to make their living. They need to be entertained, don’t be boring and bland, play out!
I have heard many players play Strauss I and Mozart back to back in auditions. Typically, the Strauss will sound good in terms of dynamics and then the Mozart is just musically flat and uninteresting. It is not supposed to sound boring.