n theory, you can play G major scale all over this, though preferably outlining the chord tones/arpeggios:
Gmaj7 arpeggio = G B D F#
Amin7 arpeggio = A C E G
D7 arpeggio = D F# A C
Playing G Major scale will result in G Ionian (Gmaj7 chords), A Dorian (Am7 chords) and D Mixolydian (D7 chords) - all the same 7 notes...
Next up, try out some more advanced colours on the dominant chord (D7) by using the
D diminished 1/2-1 tone scale = D Eb F F# G# A B C (D)
