In a new podcast McCartney: A Life in Lyrics, Sir Paul McCartney talks about his most famous songs with the poet Paul Muldoon. The podcast is aimed at “dissecting the people, experiences, and art that inspired McCartney’s songwriting.” A recent episode explored the meaning of the lyrics of the title song of the Beatles’ last album, “Let it Be.” The song arose in times of trouble. War raged in Vietnam, riots rocked the Chicago Democratic convention, and students protested all over the world…