Question: The Stanley Brothers were an American bluegrass duo made up of Ralph Stanley, and which bluegrass music lead singer, songwriter, and rhythm guitar player, he formed his band together, with his brother Ralph?
Sentence (from "Carter Stanley"): According to some historians, their recording of "Molly and Tenbrooks" (aka "The Racehorse Song") marked the beginning of bluegrass as a genre.
Relevant evidence: No