26 years after “Murder on Music Row,” George Strait joined Alan Jackson for one unforgettable final performance. Despite a storm-delayed concert and the challenges of Charcot-Marie-Tooth disease, Alan’s legendary voice still moved the crowd. When George stepped onstage, the two country icons sang their powerful anthem once more—a heartbreaking reminder of the traditional country sound they had spent their lives protecting.

Introduction 26 years after they first sounded the alarm, George Strait walked out onto a...