Apparently the piano is not a multi-timbral instrument, but in reality, being an instrument rich in nuances and potential, it allows to evoke many other sounds and many other instruments of the orchestra based on the imagination of the player.
How is it possible to imitate the sound of another instrument on the piano?
Trying to imitate the attack mode of the sound and the way of phrasing that each orchestral instrument has as its peculiar.
In the Studio da Paganini N. 5 "The Hunt" Franz Liszt explicitly suggests the evocations of other instruments, specifically flutes and horns. To be able to recreate them, it is necessary to think about the sound emission characteristics of these instruments. The flute is characterized, in its soft sounds, by an emission without an initial impulse. To have a softer, slower and "fluted" attack we should cushion the impact of the key through the elasticity of the joints, the wrist, and using the fingertip which, being the softest part of the finger, tends to cushion the attack. If, on the other hand, we played with the tip of the finger, we would create a more pointed sound, typical of the oboe for example.
Another feature of the opening incipit of this piece is that the two evoked flutes would hardly play the upper notes more sonorously than the lower ones. It is therefore useful to avoid emphasizing the upper voice, in a typically pianistic way, but on the contrary try to equate the sound level of the two voices.
Unlike the flute, the horn is characterized by a clearer, less soft sound emission, although not as aggressive as a trumpet could be. To recreate these sounds more weight has to be used, but without dampening it as we would have done for the flutes. The weight must therefore be managed softly, avoiding too clear detached sounds that horns, unlike the clarinet and oboe, would hardly be able to achieve.
And also in the case of the two horns, explicitly evoked by the author at measure n. 8, it is good to make the two voices heard equally, avoiding to highlight the upper one.
It is therefore necessary to develop the timbre imagination and try to "orchestrate" the expressive and timbric characteristics of each phrase. Thinking about a specific instrument of the orchestra or a group of instruments can be useful for us to acquire an even more focused, even more profound and effective expressiveness.
Franz Liszt: Grandes études de Paganini, S.141 N. 5 "La chasse" First edition, Breitkopf und Härtel,1851