A 1983 recording of Prince singing the spiritual “Mary Don’t You Weep” appears over the end credits of Spike Lee’s new film BlacKkKlansman, Lee revealed in a recent interview with Rolling Stone’s Jamil Smith. It soundtracks footage from the 2017 white nationalist rally in Charlottesville, Virginia, where activist Heather Hayer was killed while counter-protesting.

In the Rolling Stone interview, Lee discussed how the rare song came to his attention:

I knew that I needed an end-credits song. I’ve become very close with Troy Carter, one of the executives at Spotify [and a Prince estate advisor]. So I invited Troy to a private screening. And after, he said, “Spike, I got the song.” And that was “Mary Don’t You Weep,” which had been recorded on cassette in the mid-Eighties. Prince wanted me to have that song, I don’t care what nobody says. My brother Prince wanted me to have that song. For this film. There’s no other explanation to me. This cassette is in the back of the vaults. In Paisley Park. And all of a sudden, out of nowhere, it’s discovered? Nah-ah. That ain’t an accident.

Check out the full interview at Rolling Stone.

BlacKkKlansman hits theaters August 10. Prince and Spike Lee had a long history together. Prince did the soundtrack for Lee's 1996 film Girl 6 and Lee directed Prince's 1992 “Money Don't Matter 2 Night” video.

Prince’s “Mary Don’t You Weep” appears on the newly unearthed live album Piano & A Microphone: 1983. It’s due out September 21. Hear “Mary Don’t You Weep” below.