A heartbreaking song about a heartbreaking song is certainly a novel idea. However, what propels the track – whether it be Lori Lieberman, Roberta Flack, or The Fugees’ version – beyond the ‘power of art’ premise, is that it always carries an air of lived-in experience, a sense of awed sincerity. You really do sense that a “trembling” song came before it. And it all stemmed from one fateful night in 1971. With the Vietnam War raging, the Attica …