Beyoncé and Paul McCartney.The “Texas Hold ‘Em” singer covers the 1968 Beatles beauty “Blackbird” — written by Macca, although credited to both McCartney and John Lennon — on her countrified new album “Cowboy Carter” that was released last Friday to rave reviews (including mine) and record-shattering streams.Bey’s honey- and harmony-coated rendition of “The White Album” classic — featuring African-American female country singers Tanner Adell, Brittney Spencer, Tiera Kennedy and Reyna Roberts making like Destiny’s Southern Child — is a revelation that repurposes the song from a black female perspective.And Sir Paul has given Beyonce’s “Blackbird” — which is styled as “Blackbiird” on “Cowboy Carter” — the most royal of blessings.“I am so happy with @beyonce’s version of my song ‘Blackbird,” he wrote in an Instagram post. “I think she does a magnificent version of it and it reinforces the civil rights message that inspired me to write the song in the first place.