Appearing on the Beatles’ valedictory Let It Be album, “The Long and Winding Road” can be taken as Paul McCartney’s graceful wave goodbye or, perhaps, as a requiem for the death of the band: “You left me standing here a long, long time ago.” Recorded in the days following their final performance, on the Apple Records rooftop in 1969 -- Ringo Starr was on hiatus; John Lennon have given his notice -- the lyrical acrimony became some kind of self-fulfilling prophecy when producer Phil Spector remixed it, adding strings and a choir, much to McCartney’s dismay. “It’s a sad song because it’s all about the unattainable,” McCartney said. “I was a bit flipped out and tripped out at the time.”