Amede Ardoin' s short life and tragic death are shrouded in mystery. But the accordionists influence is still felt in the Cajun and zydeco music of today.

Amédé Ardoin shut his eyes until he couldn’t see the white faces that loomed over him like two bright lights in the dark Sunday sky. Dead in the ditch, he told himself. You’re dead, and that is why they will leave you alone.

Why hadn’t he seen these two when he left the car to walk the rest of th...