diatonic harmony in modes

[smokinguit]

By simply studying Miles Davis's So What (religiously) and other various takes by other artists I came to understand what modes are all about. It does have a sense of mystery to it as JonR pointed. But I would also add that it calms and relaxes you also. Guess that was why I couldn't stop listening to Hancock's maiden voyage when I first heard it.

[Robertkoa]

What are the disadvantages of just using

Parent Keys instead of learning A Dorian as a separate Scale ?

I don't like the sound of playing Scales too much except I do like Pentatonics ( especially with other stuff added or different endings but scale fragments sound OK).But anyway - what about this :

So instead of A Dorian I can use any structure including Arpeggios and Arp Fragments , Triads, from the Parent Key of G major including the Major Scale and the I , IV, V Major Pentatonics and their Relative Minors as long as I resolve to an A minor Chord Tone or extension ( which I would have to do anyway) .
Correct for Improvising ?

Now for Composition....( which I am actually more interested in ) Harmonically would I miss much with this "shorthand" approach ?

The "Parent Key" thing obviously works better IF you have a chordal Instrument playing the A minor Chord....in Solo Guitar you would have more responsibility to make the A Dorian Tonality or " Region"more Established ( region because it could be a Section or Vamp occurring within a Tune )...

But don't most Improvisers think Parent Key ?