Plagality is a pretty deep musical concept within tonality, though -- you have to deeply grok counterpoint and tonal harmony first, and then you can start to hear and perceive different aspects of tonal gravity.
For plagality, it's the "dark side" of the tritone, specifically with iiø or iv6.
Start putting together that tritone with the major standards of vii° or V7, and you're really rolling with the joy of traditional harmony.
For further reading, this was https://en.wikipedia.org/wiki/Hugo_Riemann and harmonic dualism.
Yeah, Rameau is the "Louie, Louie" French fellow who was the "Newton of Music" who gave us the Roman numeral notation, while the Germans were still doing counterpoint and harmonics.
I very seriously believe there's a link between that, the revolutionary attitudes and kinship of the French and Americans, with the Rock and Roll movement of the 1950s / 1960s.
Re:Toward a Better Music Theory (2013)
by AlbertCory on Saturday August 06, 2022 @07:52PM
(#32372639)
> Rameau is the "Louie, Louie" French fellow
Another win. I know Rameau and of course I know Louie, Louie, but the connection eludes me. I'm sure you'll tell us.
Instead, I kinda liked it. I took some classical piano and my teacher got very impatient with me approaching some pieces like a jazz musician would: assigning chords to measures that were quite obviously melodies over those chords. She was all about plagal cadences and all that stuff she learned at Oberlin.
The Bach Prelude in C is especially entertaining to treat that way. There's one bar near the end that it's almost impossible to give a chord symbol to.