Sascha Franck
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- The transition from a-min to D7, the 3rd of the D (F#) really pokes out, which makes sense, I guess, since that is the note that is screaming "WE STARTED ON A-MINOR BUT THAT AIN'T HOME!!!". Choosing how/when to hit that F# really determines the flavor of spice for a line bridging across those chords.
Note: There's tons of tunes using the same progression - with Am7 actually being "home". Example: Oye Como Va (Santana). Coincidentally, it's even the very same chords (Amin7 and D7). Welcome to dorian...
But anyway, apart from that, it's these very movements between thirds, sevenths and roots being responsible for the main tension/release structures within these chord progressions. Anything else is just the icing on the cake.
If you want to expand on it, I recommend playing socalled "guidelines" around these notes as their center. Just use G major material to decorate.
Here's a silly example (in Em, hence the chord here are Amin7. D7, Gmaj7, Cmaj7, excuse the lame bass and drums):