The preludes as a whole do not conform to any specific formal mold, but offer a variety of form: binary, ternary, one-part, and five-part. As such, no new formal structures have been introduced by this "first" of the nineteenth century and twentieth century "disconnected" preludes. On the other hand, they are a heterogenous collection of styles, moods, and forms--a precedent that was followed by Debussy, Rachmoninoff, and various others. To determine the degree to which Chopin was harmonically advanced would require comparative analyses of works by his contemporaries and later nineteenth-century composers. Suffice it to say that one would be hard put to locate a collection of compositions of similar length and scope, written in the 1820's, that contains the wealth of harmonic innovations found within Opus 28.