MC5 never had rap vocals like Rage Against the Machine, come on. Not the that the MC5 vocal was greatness. Rage had a great sound and especially rythym section with the bass and drum, the vocal garbage killed it for me. Sorry you have to at least try to sing, it don’t have to be Orbison. Cookie monster vocal is the same thing.
You are sure right about the influence MC5 had on bands. I think Lemmy was like ‘we wanted to be harder than the MC5!” or something.
Freegards
Check out Amorphis for a good mix of clean singing and guttural vocals.