Leroy Van Dyke remembers his hotel-room phone ringing in the middle of the night—six o’clock a.m., which, for a working entertainer, was the middle of his night. “I was asleep in a casino in South Dakota,” Van Dyke recalls. “Phone rang. It was my wife. She knew better than to call me that early in the morning, [that I was] trying to keep my pipes in shape, working at night. She said, ‘I apologize for waking you up, but I don’t think you’ll mind.’” The news Van Dyke received that morning in 1994? His 1961 No. 1 Mercury single, “Walk on By,” had been determined by Billboard magazine to be the biggest country record of all time, based on a combination of airplay, sales and total weeks (19) at the top of the country chart. “Walk on By,” an internationally popular stone-country shuffle that rings with Van Dyke’s commanding baritone and the matching low-end twang of now-legendary Nashville guitarist Hank Garland, also reached the Top 5 on the pop chart at a time when country crossover hits were still relatively rare. While Van Dyke’s memorable pair of multimillion-sellers themselves (the first being the good-natured novelty “Auctioneer,” a Top 10 country [...]