Beethoven wrote to the music publisher Breitkopf & Härtel to try and interest them in publishing the two works:
"I have composed two sets of variations... Both sets are worked out in quite a new manner, and each in a separate and different way. . . . I assure you that you will have no regrets in respect of these two works - each theme is treated in its own way and in a different way from the other one. Usually I have to wait for other people to tell me when I have new ideas, because I never know this myself. But this time - I myself can assure you that in both these works the method is quite new so far as I am concerned."Both of these works were different in the sense that they were sets of variations on Beethoven's original themes. The opus 35 set in E-flat major, written in 1802, is based on a theme that Beethoven originally used in a Contredanse about 1800. He used the same melody in the finale of the music he wrote for the ballet The Creatures Of Prometheus about the same time. Beethoven saw a great deal of potential in this theme and must have been fond of it, for after he used it in the opus 35 set he reused it for another set of variations in the finale of his Third Symphony 'Eroica' in 1803. The opus 35 set is also referred to as the Eroica Variations becasue of this. The works consists of an introduction, theme and fifteen variations, and a fugue:
Introduzione col Basso de Tema (Introduction, the bass of the theme) - The work begins with a E-flat major chord followed by the presentation of the bass of the theme before the theme itself is heard. It spans three octaves with no harmonization, just the bare bones of the bass. It is in binary form with each part being eight bars that are repeated.
A Due (Two, or double) - The playing of a bass at the beginning of a work was not unheard of, the passacaglia of the Baroque Era is one example. But what Beethoven does next is quite unusual, as he repeats the bass while an accompaniment plays in the treble. The position of the bass in this section is an octave higher than the bottom note of the bass in the introduction.
A Tre (Three, or triple) - The bass now climbs into the treble, an octave above its position in the previous section. The accompaniment becomes slightly more complex as it alternates between low notes and high.
A Quattro (Four, or quadruple) - The bass now climbs an octave higher yet as the accompaniment is spread out between the two hands. The bass has had its own mini-set of variations, and Beethoven has shown with this beginning that the bass is just as important as the theme itself.
Tema (Theme) - The preliminaries are past, the theme finally makes its first appearance with the bass fitting it well. Perhaps the audience of Beethoven's day finally got a grasp of what's gone before when the them did arrive.
Variation 1 - With running sixteenth notes in the treble, Beethoven settles in to a more conventional way to embellish a theme. Grace notes are used to spice up the theme.
Variation 2 - Sixteenth note triplets liven up the theme, and in the second section a cadenza is inserted between the two four-bar phrases.
Variation 3 - The left hand bounces from single bass notes to chords in the middle of the treble clef while the right hand plays chords higher up in the treble.
Variation 4 - Running notes in the bass while the treble plays high staccato chords.
Variation 5 - The texture gets lighter and in the second section sforzandos accent off the beat.
Variation 6 - The theme is played in chords in the treble while the bass plays sixteenth note broken octaves. The second section is written out in full as the ending of the second time around is different and segues directly to the next variation.
Variation 7, Canone all' octtava (Canon at the octave) - A canon on the theme at the distance of an octave with the bass a quarter beat behind the treble.
Variation 8 - Large jumps spread out the theme between bass and treble in the left hand while the right hand plays the accompaniment.
Variation 9 - Eighth note triplets play in thirds in the right while the left hand hammers out a B-flat preceded by the notes of the bass. The low B-flats finally rise higher in the second section while the grace notes persist.
Variation 10 - Beethoven reduces the music to two parts, almost in the style of a Bach two-part invention.
Variation 11 - A simple two note accompaniment is played while the theme plays in triplets high in the treble and drops down to the bass at the end of each section.
Variation 12 - A rising two note figure in the treble is answered in the bass with a descending two note figure. Both hands play together in contrary motion at the end of the first section. The second section has the right hand play the rising two note figure until it pauses on a B-flat dominant seventh chord. The two hands answer one another to the end of the section.
Variation 13 - Eighth note triplet chords in both hands are hammered out forte after an A natural grace note begins each measure. The second section has chords hammered out at fortissimo while the grace note changes to suit the harmony and theme.
Variation 14, Minore - The key changes to E-flat minor as a melancholy version of the theme and bass plays.
Variation 15, Maggiore, Largo - A highly decorated variation that perhaps gives us some idea of Beethoven the master of improvisation. There is a section marked Coda that can be considered an unnumbered variation. Transition material leads to the finale.
Finale Alla Fuga - Through all of the variations the bass has been as much a part of the variation process as the theme. In the final fugue the first four notes of the bass become part of the subject. The fugue is for three voices and the theme is not forgotten as it can beheard in bits and pieces throughout. The fugue segues into yet more variations on theme and bass. Beethoven rounds of the work with a short coda.