In 1819 the publisher Anton Diabelli asked several composers each to write a single variation on a fairly nondescript waltz of his own. Beethoven set the task aside for four years – possibly the collegiate nature of the commission held little appeal – but eventually returned to Diabelli’s theme, proceeding to de- and re-construct every aspect of it in a monumental set of 33 variations.

A major work, it postdates the piano sonatas and was composed at the same time as the Choral Symphony. This is late Beethoven, the deaf and obsessive composer who pushed the envelope and for whom an executant’s stamina was no longer a consideration. The variations display a double dose of virtuosity. For one thing, they stretch the pianist technically: the rapid Variations 17, 25 and 28 are as dazzling and difficult as any of Chopin’s Etudes. They also showcase the brilliance of Beethoven’s musical imagination.

Paul Lewis has recorded Beethoven’s sonatas and concertos to great acclaim. While he responds to the gradations of tone and dynamics required, he is more “old-school” than some other young pianists (Brendel was his mentor). Some critics have found Lewis stolid, even dull: I don’t think so at all. His playing has underlying strength, giving his interpretation a satisfying cohesiveness. 

Piotr Anderszewski (Virgin) offers a mercurial, wonderfully detailed reading: his modernist Diabelli Variations is a series of close-ups, examining all the mischievous wit and introspective melancholy of late Beethoven. In contrast, Lewis sees the work as an edifice. Both recordings are indispensable.