[6 Piano Pieces, Op. 21] I. Prelude [6 Piano Pieces, Op. 21] II. Fugue a 4 voix [6 Piano Pieces, Op. 21] III. Impromptu [6 Piano Pieces, Op. 21] IV. Marche funebre [6 Piano Pieces, Op. 21] V. Mazurque [6 Piano Pieces, Op. 21] VI. Scherzo [6 Untitled]