Some things just bear repeating: between Aretha, Bowie, Leonard Cohen and Prince, popular music has lost some towering and boundlessly influential figures in recent years. In March, perhaps the most inimitable of them all passed on, leaving behind a legacy that, above all else, remained impervious to second-guessing. Over six decades, Scott Walker emerged as an auteur effortlessly wielded progression, enigma, and subtlety like no other. From fronting L.A. pop trio The Walker Brothers in the 1960s right up until his sublime score for Brady Corbet’s Vox Lux last year, he steadfastly broke new ground, contorted boundaries and followed one of most remarkable trajectories in popular music.…