 However, Liszt perfected the creation of significantly longer formal structures solely through thematic transformation, not only in the symphonic poems but in other works such as his Second Piano Concerto and his Piano Sonata in B minor.In fact, when a work had to be shortened, Liszt tended to cut sections of conventional musical development and preserve sections of thematic transformation.Between 1845 and 1847, Belgian-French composer César Franck wrote an orchestral piece based on Victor Hugo's poem "Ce qu'on entend sur la montagne".