"Variations on both popular and original themes were a kind of ''fashion accessory'' during the days of Viennese classicism, and Beethoven also made his contribution to this genre to be sure, financial reasons played a role here, as fashion articles sold well. Yet little by little, the principles and formal layout of the variation form assumed a central meaning for Beethoven.
This second volume of the Henle Urtext edition featuring Beethoven's complete piano variations contains, as it were, his ''master variations.'' Whereas two of his earlier variation cycles had ben published without an opus number, these were followed by opp. 34 and 35 - pieces which Beethoven mentioned in a letter to the publishing house Breitkopf & Hartel and which he felt were ''crafted in an utterly new and different manner.'' The most momentous works in this category are the 32 Variations in c minor WoO 80 and the celebrated Diabelli Variations op. 120, two pieces that count among the most important variation cycles ever w itten. "