It's possible to hear the progression of soft rock through the music of Seals & Crofts, the duo who recorded some of the genre's perennials. Over the course of the 1970s, Seals & Crofts evolved from a gentle folk-rock duo to purveyors of slick, polished pop, two sounds that became inextricably associated with the Me Decade. Practitioners of the Baha'i Faith -- at the height of their fame in the mid-'70s, they'd extol its virtues to fans -- the duo were drawn to the quieter aspects of rock music, developing a signature sound distinguished by their easy melodicism and mellow vib...