Keys, operations, intersections, bendy notes in tunes

This is also what I vaguely remember from Ros.

Something about...
Take a scale. do something to it. compare it with your first scale. what's interesting?

Also something like:
Take a 10 note cycle of fifths. take 2 out. Then there's something interesting left over.

Also something observed:
the above somehow relate to where keys are most bendy chromatic runs in baselines under predominantly diatonic or modal music - backing trad.

Most bendy places are:
3rds, 6ths, 7ths, 9ths or 2nds,

e.g. in G:
Bb, B, Eb, E, F, F#, Ab, A

Organised by fifths: A, E, B, F or 9ths/2nds, 6ths, 3rds, 7ths

Steph note: within the four common modes that get used in trad, these are the points in the key that give it it's emotional colour. The notes that do not bend include 1, 4, 5 and create the structure.

** Compare this with where a blues scale gets bent ??