These lifelong friends pretty much hated each other by the time their fifth and final album came out. Simon wrote most of the songs while Garfunkel was acting in Catch-22, and when they got together to finalize material they feuded endlessly. (Garfunkel vetoed a song about Nixon; Simon overruled a Bach chorale. Call it a draw for them and a victory for listeners.) What made it onto the album are some of the duo’s saddest melodies (“El Condor Pasa,” “The Only Living Boy in New York”) and most buoyant harmonies (“The Boxer,” “Cecilia”). Only Garfunkel sang on the title track, which, according to BMI, was the 19th most performed song of the 20th century, spawning versions that run the quality gamut from Aretha Franklin’s transcendent cover at the Fillmore in ’72 to Clay Aiken’s considerably less transcendent cover on American Idol in ’03.