The first theme is a descending scale marked "sotto voce"; full of ominous undertow. It reappears at crucial points in the work's structure. This leads immediately to a jagged, forceful motif in octaves. This is quickly followed by a hammering "marcato" motif in the left hand. A dialogue ensues, with mounting energy, until reaching the noble Grandioso material in D major. Liszt transforms the "marcato" motif into a lyrical melody later. The slow movement, an "Andante sostenuto", is the centerpiece of the Sonata. This fully-fledged movement, in compound ternary form, features, in quick succession, a number of themes heard earlier in the Sonata in a "tour de force" of thematic economy. The final recapitulatory section is launched by a driving "fugato" of contrapuntal skill which leads to the compressed return of the opening material. Calling upon every intellectual resource and fully exploiting the pianist's technical arsenal, it is at this point where a performer's concentration might wane. But this final section has just begun, and a pianist needs to have reserved fuel in their tank if he is to turn in a successful performance of the Sonata. Each of the sections are examples of Classical forms, which means that this piece is one of the first instances of Double-function form, a musical piece which has two classical forms happening at the same time; one containing others. Already in 1851 Liszt experimented with a non-programmatic "four-movements-in-one" form in an extended work for piano solo called "Grosses Concert-Solo". This piece, which in 1865 was published as a two-piano version under the title "Concerto pathétique", shows a thematic relationship to both the Sonata and the later "Faust Symphony".