Chopin’s 1841 Fantaisie in F minor contains echoes of a Polish revolution song from the November Uprising of 1830 that led to his lifelong exile in Paris. Dignified and contemplative, it combines clearly-structured sections with more improvisatory-feeling ones. His Polonaise-fantaisie of 1846 equally blends dance and improvisatory elements. Shostakovich’s No. 15 Prélude of his Bach-inspired 24 Préludes and Fugues (1950-1951) is unusually tonal for him and the set, but the ensuing fugue is highly atonal, its difficulty heightened by its subject switching metre four times; yet it ends on surprise tonal chords. Prokofiev’s Sixth Piano Sonata opens full of his characteristic strong rhythms, which take on a mechanised tone for the following Scherzo. Next comes a lyrical waltz, before the final movement sits an Andante between two urgent Vivaces.