Prince would have turned 60 today (June 7) had he not died of a fentanyl overdose in 2016. The late musician’s estate commemorated his birthday by unveiling plans for a new minimalist solo album.

According to an announcement on the estate’s Facebook page, “Piano & A Microphone 1983” will arrive on September 21. Per its title, the album features nine cassette recordings that Prince created with just his voice and piano during a 1983 session in his home studio. He made the recording while workshopping material ahead of the 1984 release of “Purple Rain.”

“The private rehearsal recoding, captured at Prince’s home studio in Chanhassen, Minnesota, provides a rare, intimate glimpse into the iconic artist’s creative process as he works through songs including ‘17 Days,’ ‘Purple Rain,’ ‘Strange Relationship’ and ‘International Lover,’” reads the Facebook post.

Listen to one of the album’s tracks, “Mary Don’t you Weep, via Spotify or your streaming service of choice. Pitchfork reports that this version of the spiritual will appear in Spike Lee’s “BlacKkKlansman.”