Excellent question: The chords in the progression pull from the 1 (G minor) and eventually returns there. Now there is a technique in modal jazz/smooth jazz and I forget the name right now where you basically select a central tone or scale and use that tone or scale throughout the whole progression. In this instance it would be the G minor chord because the song starts on the G minor and eventually resolves to the G minor. Plus there are tones in the G minor scales that you'd use that are common to all of the chords in the progression.
Now from sing chord scale analysis you have a few choices for what scale you'd want to use for the G minor.
You have G Dorian which is F major scale that starts and ends on the G
You have G Aeolian which is Bb major scale that starts and ends on the G
You have G minor pentatonic scale which is a Bb pentatonic scale that starts and ends on the G
You have the G Blues scale which is the G minor pentatonic scale with an added #4 (C#)
there are more choices but these are a good start...
I chose to go with the G minor pentatonic scale because it's more melodic and doesn't sound so much like you're running scales up and down the keyboard and there are also fewer notes to choose from and use.
Now a good technique or tip for soloing would be to use the notes from the scale as a pool of notes to use. Try to start and end on different notes within the scale and try to be as melodic as possible like singing but using the piano to sing for you. I'm still learning this but some guys that I like to listen to for this is Jeff Lorber, Alex Bugnon, George Duke, Herbie Hancock. Especially Jeff Lorber is the master of taking that pentatonic scale and exploring all of the melodic possibilities..
If you'd like some more info and example on uses of the pentatonic scale which is really THE go to scale that all of the pros use, check these YouTube Videos out:
Funk Lesson - using the pentatonic scale to solo http://www.youtube.com/watch?v=D16Egf419YY
Pentatonic Scale in 5 minutes - this guy shows you the pentatonic scale and how to use it also what chords to play the pentatonic scale over http://www.youtube.com/watch?v=rVYky3cNC_Y
If anyone needs more help in this area let me know!!
This iz very helpful. Be blessed
