In 1819, Viennese publisher and composer Anton Diabelli asked a dozen or so well-known composers, including Beethoven, Czerny, Hummel and Schubert, to write a variation each on his own Waltz in C major for a planned collective edition for piano. At first, Beethoven was reluctant, then he procrastinated as usual; after some time, however, he presented Diabelli with a gift as magnificent as it was unexpected: a great cycle of 33 Variations. It goes without saying that the happy initiator of the venture published Beethoven’s work separately as 33 Veränderungen über einen Walzer von Anton Diabelli op. 120 in 1823. This is not only Beethoven’s greatest achievement in variation form; it is also one of the most remarkable examples of the genre in the entire history of music. Diabelli’s simple and hardly original waltz became a pretext for unfettered flights of fancy. Beethoven used all variety of variation. Already in the First, he turned the waltz into a march; the Second is based on a single textural idea: a toccata change of both hands, with some articulation in piano dynamics. Variation IX is consistently constructed on a motif taken from the waltz’s upbeat, while the next, in Presto, surprises with long chord chains over long trills in low register. Variaton XX, quiet and calm, almost entirely maintained in equal values, is sandwiched between two rapid and highly dynamic variations. The relationships with the original theme are so distant as to become illusionary. This freedom of variation allowed Beethoven to use, in Variation XXII, a quotation from Leporello’s aria “Notte e giorno faticar” from Mozart’s Don Giovanni; in another display of virtuosity (Variation XXIV), polyphony – which has already appeared before, if only occasionally – appears in its strict form of Fughetto. Highly unusual is the combination of the three final variations: a highly ornamented Largo, molto espressivo, much in the spirit of the last sonatas, a great double fugue and a whimsical Minuet, dissolving in ethereal passages.