Sure, but the flip side is that every scale now has one repeated letter and at least one sharp or flat. Take C major; in hypothetical 6+6 notation, it becomes

Sure, but the flip side is that every scale now has one repeated letter and at least one sharp or flat. Take C major; in hypothetical 6+6 notation, it becomes C D E E# F# A# B# In fact, I think every diatonic scale in 6+6 notation will have three or four sharps/flats.