Nuño Fernández, Luis; The Harmonic Wheel is here used to represent single chords, excerpts and full harmonies from different musical styles, considering both triads and seventh chords, and including modulations. In some cases, the harmonies followed one of the three cycles defined by the consonant intervals and, in others, they were diatonic to a particular key. In all cases, the Harmonic Wheel has proved to be a powerful and versatile tool for representing the harmonies and, therefore, to show the underlying structures of the musical compositions here considered. Furthermore, it provides an efficient mnemonic notation by means of simple and compact diagrams. http://hdl.handle.net/10251/194201