From his modest ‘Dressler’ divisions of 1782, the enquiry of an eleven-year-old, to his stupendous ‘Diabelli’ cycle of 1823, the answer of a man into his fifties, Beethoven’s principal sets of variations for piano (twenty in all) span a creative period actually greater than that of the thirty-two sonatas. As much for their demonstration of an expanding compositional technique as for their sense of innovation (their progressive replacement, for instance, of the notion of a ‘theme’ by one of a ‘thematic unit’ – a germinally, permutationally richer conception), they stand patently as the finest examples of variation writing in the Classico-Romantic era. The Bach ‘Goldberg’ was their grand inheritance, the Brahms ‘Handel’ their monumental consequence.