Concerto for Solo Piano (French: Concerto pour piano seul) is a 3-movement solo piano piece written by Charles-Valentin Alkan. The pieces are part of a 12 piece cycle entitled Douze études dans tous les tons mineurs (12 Studies in the Minor Keys), published in 1857 (although it may have been written some years earlier). With sections marked "Tutti", "Solo" and "Piano", the piece requires the soloist to present the voices of both the orchestra and the soloist. The pianist Jack Gibbons comments: "The style and form of the music take on a monumental quality—rich, thickly set textures and harmonies ... conjure up the sound world of a whole orchestra and tax the performer, both physically and mentally, to the limit."
The work features progressive tonality, beginning in G-sharp minor and ending in F-sharp minor; this is a consequence of the piece being three consecutive elements of the cycle of 12 études, each of which is in a key a perfect fourth higher than its predecessor.
The piece, including all 3 movements, is 121 pages long and takes about 50 minutes to perform. The first movement on its own, comprises 72 pages and takes over 29 minutes to play (Jack Gibbons comments that "the first movement has more bars in it than the entire Hammerklavier Sonata by Beethoven"). Alkan authorized the piece to be truncated to make "un morceau de concert, d'une durée ordinaire" (a concert piece of normal duration). It may be that the composer himself performed the first movement (alone) in such a shortened version in a recital in Paris in the 1880s. It was not until in 1939 that Egon Petri gave the piece a proper performance, in its entirety, during BBC broadcasts.
Adrian Corleonis considers the Concerto to represent the most cruelly taxing piano work before the time of Kaikhosru Shapurji Sorabji and Ferruccio Busoni.
The first movement, which requires almost half an hour to play and has 1342 bars, is marked "Allegro assai". Performance demands tremendous physical endurance, and great technical skills to cover features including arpeggios, octave runs, scales, leaps, grace notes, alternating hands, swiftly changing block chord motifs, tremolos, and 4-5 trills with the melody played on the same hand. Alkan stays close to the classical sonata form, using a double exposition, but the exposition and development sections are expanded greatly.