Started studying the physics of intervals today. It is fascinating that the Perfect Fifth corresponds to a frequency ratio of $3:2$.
If our fundamental frequency is $f$, the overtones are:
$$ f, 2f, 3f, 4f, 5f, \dots $$This explains why the Major Triad ($4:5:6$ ratio) sounds so stable.
Working on "Autumn Leaves" but focusing on voice leading the thirds and sevenths. Here is a shell voicing idea I was working on for the $ii - V - I$ in G minor ($A^{\varnothing}7 \to D7_{alt} \to Gm6$).
I recorded a quick improvisation over these changes to check my phrasing.
Looking into Ernst Levy's concept of negative harmony. If we rotate the circle of fifths around the axis between $C$ and $G$ (the root and the fifth), we map intervals to their "negative" counterparts.
The mapping function $N(x)$ can be described as reflecting the pitch class across the axis.
$$ C \leftrightarrow G $$ $$ E \leftrightarrow Eb $$
Thus, a C Major triad $\{C, E, G\}$ maps to a C Minor triad (inverted) $\{G, Eb, C\}$.