Arpeggios
G arpeggio = G B D
E7 arpeggio = E G# B D
Am7 arpeggio = A C E G
D7 arpeggio = D F# A C
In theory, when soloing you can play G major scale over all the chords, except the E7 where you'd switch to A harmonic minor.
Scales
G Major - G A B C D E F#
A Harmonic Minor - A B C D E F G#
Playing G Major scale will result in G Ionian (G chords), A Dorian (Am7 chords) and D Mixolydian (D7 chords) - all the same 7 notes...
NOTE: It's only a two note difference between G major scale and A harmonic minor scale - as the G becomes G# and the F# becomes F - the rest of the 7 notes stay the same.... easy!!
Next up, I'd recommend trying out some more advanced colours on the dominant chord (D7/D13) by using the
D diminished 1/2-1 tone scale = D Eb F F# G# A B C
And you can also try out the Altered Scale (Superlocrian) on E7! E Superlocrian Mode - E F G G# Bb C D
