I’ve just read The Stories of English by David Crystal. Which I’d recommend as an interesting read. He quotes some of a C12th poem called the Ormulum, after its auther, a monk called Orrm. It’s written in alternating unrhymed lines of 8 and 7 syllables – iambic tetrameter and iambic trimeter with a feminine ending. Or alternatively in long 15 syllable lines with a caesura, depending how you prefer to print it. Which didn’t catch on. Might be worth experimenting with, though. Sort of nearly ballad metre.