Chopin: Twenty-four Preludes, Op. 28 In the Romantic era, “preluding” was a common practice. Before or between set pieces on a program, the pianist would often improvise a brief prelude, to establish the mood and key. Chopin was an expert at that art, but his composed Preludes were quite different, and as such somewhat confounding to his contemporaries. The set of 24 short pieces—one in every key—wasn’t intended as a compilation of introductory material, but rather a complete cycle unto itself. In that way, many have noted, they took more inspiration from Bach’s Well-Tempered Clavier—also a set of keyboard works in every key—than from the traditional Romantic conception of a prelude.