So What is pluralism anyway? Well, when we talk about pluralism in a harmonic context it means that a single chord can have multiple names and functions. For example If we examine a D-9 chord: D – F – A – C – E. Then remove the root we have an FM7 chord. This is the concept of pluralism applied to the harmonic language of music. Some chords have complete pluralism. Like CM6 and A-7 : C – E – G – A. These notes when arranged in this order function as a CM6 chord. However, When the notes are re-arranged: A – C – E – G. Now, the notes spell a completely different chord. A-7. These two chords have complete plurality. In other words: they share ALL notes. They could be substituted for each other in the right context.Or depending on the function of the harmony you might see the first one and consider IT to be a first inversion A-7 chord.