For the next see post 204
The celtic 6-notes minor scale 2-2-3-2-2-1 is a subscale of the 7-notes diatonic scale 2-2-1-2-2-2-1
The Greek pentatonic (5-notes) scale 2-2-3-4-1 is a subscale of the Celtic 6-notes minor scale.
But also the India or Egyptian pentatonic scale 2-2-3-2-3 is also a a subscale of the 6-notes celtic minor
This allows for interesting improvisations shifting from
1) Ionian more of diatonic 2-2-1-2-2-2-1
2) Celtic minor 2-2-3-2-2-1
3) Greek pentatonic 2-2-3-4-1
4) Indian pentatonic 2-2-3-2-3
where in all cases the 3 first notes and interval structure in semitones 2-2 remain stable
