Extreme Chord Substitutions: a Qualitative Introduction to CAT (Cataldo Advanced Transformations)

In this article we briefly introduce an original method, the purpose of which fundamentally lies in providing musicians with a reliable instrument that may effectively assist them in carrying out the chord progressions analisys. The method is primarily based upon the application, carried out by following a specific order, of a set of transformations, named CAT (Cataldo advanced Transformations), by means of which any harmonic progression may be converted into a mere sequence of plagal and perfect cadences. The above-mentioned transformations, nothing but particularized inverse chord substitutions, arise from the analisis of a considerable number of traditional jazz compositions, carried out by accurately examining the so-called LEGO Bricks. It is worth underlining how the description of CAT herein provided is to be considered as being merely qualitative, since the formal definition of the transformations would require the usage of an extremely rigorous notation, elsewhere exploited in order to introduce the so-called Music Algebra.