G-B-D-F (turnaround) or G-B-D-E# (otherwise) 31-edo supports free modulation as well as 12-et does, with a caveat or two. For example, you can't play Coltrane's Giant Steps in 31-edo, becuase Giant Steps' chord progression relies on the fact that 12-edo's way-too-wide 400-cent major third tempers out the diesis , so that a