Glen Campbell may have debuted in the early '60s as a dazzling session guitarist and singer—working for the likes of Elvis and Sinatra, and sometimes even taking Brian Wilson's place onstage in the Beach Boys—but he wound up rivaling any of his former clients as a hitmaker once he finally stepped behind the mic as a solo artist. Deploying his velvety croon as the urbane muse for songwriter Jimmy Webb, the Arkansas-born Campbell polished his early crossover smashes so exquisitely that Nashville's country purists barely accepted them. His string-laden epics, like "Rhinestone Cowboy" and "Wichita Lineman," would steer the genre toward the pop dominance it still enjoys. But they were also haunting character studies that would eventually shape sounds as distinct and distant from Music Row as the thunderous power ballads of Guns N' Roses and the hushed alt-rock mystery of R.E.M. As a late-career performer, Campbell acknowledged his own encroaching mortality with astounding gravity and grace, searching for salvation in a tender hymn by punk progenitors The Velvet Underground and singing with the heartbreaking vulnerability of a man staring down life's finale.