The way I see this is that we do this anyway ... imagine bass playing by root and fifth
in a ii v i progression based around c, you’d play D and A, G and D followed by C and G. To make it more interesting you’d throw in some chord notes such as F from the Dm, the A as a passing note in the G and do on
that’s a mode, isn’t it ? D Dorian right there..then G mixolydian