John Michael Montgomery's voice was one of the most commercially powerful instruments in 1990s country music. 'I Swear' crossed over to become a global pop phenomenon, and his string of hits made him one of the decade's biggest stars. Then the voice began to fail—and Montgomery retreated from public view. The story behind his gradual disappearance from the spotlight involves vocal damage, personal struggles, and the particular cruelty of an industry that discards artists the moment their instrument falters. Montgomery's career is a reminder that the human voice is fragile, fame is temporary, and Nashville's memory is short. • How 'I Swear' crossed over from country hit to global pop phenomenon • The vocal damage that gradually silenced one of the 1990s' most powerful voices • Why the industry offered no safety net when his instrument began to fail ...