Hello. I'm new to music theory and am interested in knowing more about a topic hinted at in a couple of Guni's (well-written, BTW) articles: stability.
From Guni's article on solfege, I've inferred that the root, major third and perfect fifth are "stable notes" and other notes resolve to them, making the other notes essentially "unstable." This sort of makes sense to me as the major triad is the first building block of western music. Is this correct? If so, why are certain notes stable, and others not? Also, are some notes more unstable than others? Guni alluded to a tension curve, what is that?
In Guni's triad article, he lists out different chords of various stability. How do you rate the stability of a chord? Is it based on how the notes in the chord relate to the parent key? Is there a preference for the position within the chord for determining a chord's stability? For example, the V chord is built from P5, M7 and M2 of the key, so by my recogning, it would be stable, unstable, unstable. But the mII chord would be built from the M2, P4 and M6 of the key, so wouldn't that be less stable than the V chord? What am I missing here?
Thanks for any and all help.