Completed in October, 1809, the Fantasia for Piano in G minor, Op. 77, was commissioned by Muzio Clementi (1752-1832), whose London publishing firm printed the work in 1810. The piece is dedicated to Count Franz Brunsvik (1777-1849), a capable cellist. Beethoven, always trying to maximize his income, also sold the publication rights to the Fantasy to Breitkopf & Härtel in Leipzig, whose edition appeared in November, 1810, only two months after Clementi's in England. That Beethoven composed this flight of fancy when he did is somewhat ironic, for he was attempting, for the first time in his life, to settle down, live without hotels and restaurants and to establish a real "home" where he would sleep and eat his meals.
Carl Czerny (1791-1857), a composer who studied piano with Beethoven in 1801-3, described the Fantasy, Op. 77 as variations "in a mixed form, one idea following another as in a potpourri, ... " Possibly no other work reflects Beethoven's tendency toward improvisation. Czerny's assessment is apt. The Fantasy passes through eight key areas, three changes of meter and numerous changes in tempo. What is most curious is that the piece, mostly a string of seemingly unrelated vignettes, closes with a self-contained section a half step higher than the fundamental key at the opening of the piece. One senses an anticipation of relaxed Romantic-era fluidity and freedom.
Rapid descending scales and drastic tempo changes mark the introduction, which hovers around the keys of G minor and A flat major before committing to the dominant of B flat major, the key of the ensuing section. Marked Allegro and in 6/8 meter, the new segment is the first to have a real theme, but it quickly dissolves and modulates to D minor for the first of what seems as much a finger exercise as new theme, this time stressing arpeggios. D minor continues through the next idea, in 2/4 and featuring a theme outlined by broken octaves alternating between the hands--one of a pianist's nightmares. This section ends abruptly and, with one chord, moves to A flat major for the next idea, marked Adagio and with a repeated-note theme over changing harmonies. A loud, Presto bridge introduces new material in D major, propelled along by the 6/8 meter. This section consist of two ideas, the first a theme played in block chords in the right hand, the second consisting of running eighth notes in both hands, the theme from the first part played by the little fingers of each hand. Suddenly, the Adagio repeated-note theme returns, but on the dominant of B major, preparing the arrival of the self-contained, variation-like section that will close the piece.
The new Allegretto theme resembles the repeated-note Adagio theme, but is more active. It is followed immediately by a frantic idea broken between the hands but eventually smoothes out into another exercise-like figure. Broken octaves return in this quasi-developmental passage, in the middle of which the Allegretto theme appears deep in the bass then in repeated chords in the right hand over a leaping, diving bass line. After a few rapid flourishes, the Allegretto theme sounds in its original form, but in C major, a key that lasts only a few measures before B major takes over and the piece closes.