Through the Études we can see the evolution of Franz Liszt as composer and pianist.
This genre was very important for Liszt, as were the Sonatas cycle for Beethoven or the Mazurkas cycle for Chopin. The only genre upon which Liszt worked throughout his life was the Études: the first were written when he was fifteen years old, the last when he was in his fifties, although he was still writing cadenzas for some of them until his death at the age of seventy-four.
The first Études Opus 1 were written under the influence of Carl Czerny, Liszt’s only piano teacher and himself a student of Beethoven, with whom Liszt studied for a short time.
The next chapter of his relationship with the Études opened under the impression of violinist Niccolò Paganini. These Études went through different stages of evolution and sometimes exist in three quite different versions. However, my favourite is the earliest version of the Études written on Paganini themes, not because of the number of notes or their technical difficulty, but because the earliest version still preserves the charm of improvisation, which was subsequently transformed into the thematically detailed and logically developed composition of later Études.
The Transcendental Études again exist in several versions, for instance the ‘Mazeppa’; however, the main idea of his composition takes its roots from Liszt’s first Études Op.1, rewritten through the evolution of Liszt’s pianistic and compositional style.
The Three Concert Études and Two Concert Études were the only Liszt compositions written on his original themes, and represent the peak of his compositional style. My favourite is the first of the Three Concert Études, the biggest and longest of all written by Liszt, though unfortunately rarely played. Also most attractive for me are the cadenzas and the ending of the D-flat major Étude. These cadenzas where written by Liszt’s own hand in the scores of his students, and prove the fact that Liszt himself often changed the text spontaneously according to his mood or the student performer’s technical needs, and played differently from the way the music was published in the score.
It is important to bear in mind that Liszt’s music was not limited by notation, and sound was hugely different from that produced by modern-day pianos. If I consider the Étude en douze exercices, the ideal piano sound could be achieved from an early Erard or a Viennese Graf; whilst for the Études d'exécution transcendante d'après Paganini, again a Viennese Graf piano, which sounds very light like a harp, may provide a suitable sound aesthetic.
The Grandes études de Paganini, Douze Grandes Études and the Études d'exécution transcendante could represent a great but different sound palette on Boisselot or Erard pianos, and the Concert Études on Boisselot, Erard or Bechstein pianos.
Liszt himself tried many different instruments in terms of their sound and mechanical action. One of his favourites was Boisselot, however when he was at the moment of spontaneous inspiration Liszt was able to play on anything that had the keys, and the size, age of instrument, sound and technical action were secondary. The primary element was Liszt’s moment of spirit, creation and inspiration.