Is there one? I want a bard for a non-magical continuity. What if I replaced the spells with the warriors weapon group abilities or the Gunslingers grit? Would that be OP?
I think the OP wants to preserve the bardic performance ability, or am I wrong? To me, that is what puts the bard in bard. I could imagine a non-magical bard that replaces spells with some investigator abilities, and perhaps more bardic performance rounds and the ability to maintain more than one bardic performance at once at higher levels.