It’s been 40 years since The Beatles released “Let It Be.” The song ended up as the title track of the last album the group ever released together. “Let It Be” was named number 20 on Rolling Stone’s “Top 500 songs of All Time List” and continues to be covered, even as recently as a few months ago by Jennifer Hudson during the Haiti recovery effort.

We talk with singer-song writer Roberta Flack, currently working on an all Beatles cover-album tentatively called “Let it Be Roberta,” about why the much covered song is still so beloved.