Producer Joe Boyd (Pink Floyd, Fairport Convention/Richard Thompson, R.E.M.) has written a massive, highly entertaining, illuminating book about world music called And the Roots of Rhythm Remain, the title a lyric from Paul Simon’s Graceland song “Under African Skies.” That album is a jumping-off point for Boyd’s explorations of music from around the globe, with stops in Jamaica, Cuba, Brazil, India, Russia and Eastern Europe as well as the southern U.S. Here Boyd tackles such questions as: How important is cultural cross-pollination to music’s growth? Where’s the line between proper and improper cultural appropriation? What roles have oppression and religion played in great music? Boyd, who was stage manager at the 1965 Newport Folk Festival as Bob Dylan went electric, also weighs in on A Complete Unknown: what was true, what was false and what may have been false but felt true. And he has a few words about R.E.M.