Johannes Brahms wrote his Variations on an original theme as the no. 1 of his Op. 21. The work was finished in 1857, written in the key of D major and consisting of 12 sections. It was first performed in 1865 by Clara Schumann. The theme is a beautiful melody in D major, presented in a rich contrapuntal setting that leaves it almost over-supplied with possibilities. However, Brahms concentrates on the theme’s harmonic structure to provide a framework for fresh invention—though paradoxically the harmonic structure is itself dominated and somewhat restricted at each end of the theme by a pedal bass, whose implications are sometimes accepted and sometimes ignored. There are eleven variations, and all except the last are confined to the theme’s unusual dimensions: two nine-bar halves, each half repeated.