When the Prince Estate hatched plans for the upcoming Piano & A Microphone 1983 album, due out Sept. 21, it tapped Revolution keyboardist Lisa Coleman to write some liner notes. It's an appropriate choice, of course. The classically trained Coleman, who worked with Prince from 1979-86 and remained on good and even collaborative terms subsequently, has a valuable perspective about Prince's creative methods and piano playing and had a front-row seat for when he was recording these feeling-out versions of future favorites such as "Purple Rain," "17 Days," "International Lover" and others, as well as the version of the spiritual "Mary Don't You Weep" that's also featured in Spike Lee's new film BlackKklansman. Currently on the road again with the reconstituted Revolution, Coleman took a few minutes to talk to Billboard about what was a moving and insightful experience...

Billboard: What was it like to get a chance to comment on these recordings?

Lisa Coleman: It was really interesting. It's really amazing that this cassette, out of all the hundreds that exist, somehow rose to the top, and it's actually a really interesting tape. It's really cool, and it's just...Prince, in my opinion. He's kind of stretching out and getting to know some of the songs that the band wrote. He kind of took them and was exploring them alone and playing with the time signatures and the feels and the songs. It's really interesting to hear these songs presented and explored in different ways. This kind of thing was standard operating procedure for Prince, wasn't it?

Oh, yeah. It was not uncommon. There was always a tape rolling, whether it was video or cassette or DAT or even a 24-track. I'm just amazed that this one, or any of them, survived. It's really cool. Talk about what you hear him doing on these recordings?

Listening to this tape is kind of like watching a soccer player warm up with a soccer ball -- they just kick it around and bounce it off all the different parts of their body. They're focusing. They're alone, even though it's a team sport. In his mind he was always creating for huge audiences and playing to the world, but at this moment it's just him and the songs and it feels like just you he's talking to. It's so intimate. It's really just him and a piano.

Was it a heavy emotional experience to hear this?

Oh God yeah. I didn't want to do it. It was hard and I cried, and just hearing his voice at the beginning of the tape, when he tinkles around and he's talking to one of his engineers and just speaks into the mic...Just hearing his voice like that, it was wonderful to hear and it was painful. It was instant time travel. But I was honored that they asked me to do it, and I care so much about it that I really felt like I had to take it on, so Prince would know I really care and I really understand him as a musician. I just hope the liner notes are good; I think I'm a better writer than that but I couldn't get it together in my brain because it was so emotional. All I could do was cough up a bunch of thoughts. What kind of revelations did you experience hearing this?

There were a couple of moments like that, for sure. As a musician I was taken by when I could tell he was playing and got into a comfort zone. He would just kind of play for a couple of minutes and you could feel like, "Oh, he's gonna do a long ump now..." He explored a lot harmonically and you'd hear him get frustrated when it didn’t go where he wanted it to go, but it went halfway. Then he'd go back to the groove and kind of pivot and start again. Musically there are interesting moments like that. Which of the songs resonate with you in particular?

At the very end, "Why the Butterflies," that one really struck me because I think that was completely unique to that moment. My instincts tell me that, even though musically, it wasn't completed the seed for "When Doves Cry." He sings out to his mother and he says, "Why the butterflies," and it just reminds me of "you've got the butterflies all tied up..." It's like, "Oh! That was on your mind for awhile," because that song was kind of towards the end of the Purple Rain project, and it was something he did all by himself, and it was so personal. Even though he wrote a lot about his family and religion and things like that, I think "When Doves Cry" was on a different level, really exposing him and almost like a psychological, self-help kind of song.

There are likely a lot more of these kind of Piano & A Microphone cassettes around, too.

Yeah, absolutely. That's why some people are asking if it was unusual for him to do this. No, it was not unusual at all. so there's got to be lots of those. Cassettes and musicians were lovebirds back then. Any insight into some of what else is in his vaults and what you'd like to see come out?

There's a lot of material in the vaults from live shows, videos and recordings. That kind of stuff would be fun to get into and maybe revisit. Inside the band there's a famous jam called "Ice Cream." When Prince was in a good mood or we were having a good show he would sometimes just run to the microphone and scream "Ice Cream!" and that was a que for us to go into this particular jam thing, and that's never been released or heard or really known. There were lots of little things like that we would do. Those kinds of things are really fun, and I'd love to share that with the public. We'll see. There's, like, 100 years’ worth of material in that vault. Meanwhile, you and the Revolution are sharing the music on stage. That seems to really be working out for everybody.

It's great. It's totally unexpected. It's hard to think of it as being, like, a tour and being successful and stuff like that right now because we're in a weird spot where we're transitioning from coming together out of grief and just pure shock and we're in the middle of, "Now what? Why are we doing this? What's it for?" We're still getting our heads around it.