Here it goes...... FMaj////GMaj////FMaj////GMaj.......... At first glance you could play F Ionian////G Ionian////, etc.......... But there's got to be an easier way to compliment the progression and focus on highlighting the notes as the progression changes.
FMaj = 1-3-5 (F-A-C) GMaj = 1-3-5 (G-B-D)
Let's look at the F Ionian mode = 1-2-3-4-5-6-7 (F-G-A-Bb-C-D-E)
All of the notes fit except for that damn 4th interval (Bb) and it's not even used in the FMaj chord!!!!!!! That 4th interval would need to be # from Bb to B and it would work for both chords. Let's try again this time using the F Lydian mode = 1-2-3-#4-5-6-7 (F-G-A-B-C-D-E) Hey that works!!!!!!! Many players would argue and say you could just use the C Major scale and it would work the same way, but I view it differently. The progression begins with FMaj and moves up a Major 2nd to GMaj giving the progression it's own entity. Modal progressions usually use 2 or 3 chord structures and resolve to the root chord so it remains the tonic or home chord of the mode emphasized.
Try a ________ mode and combine a minor/Major progression:
Dm7////Dm7////FMaj7////CMaj7............... What mode would fit here?