Jake Brown

“Expanding further on his own observations of Prince’s writing style(s) during the course of the album’s recording, fellow Paisley Park engineer Eddie Miller, who engineered the recording of ‘Electric Chair’ among other Prince recordings during the Batman era, recalled that “he would write all sorts of ways. I have to admit that I listened to some of his cassette demos that he would sometimes bring into the studio to reference (as I remember, he would hold the cassette player up to his ear, so you couldn’t really hear it.). They were fascinating. His cassette demo technique was extremely crude but ingenious—it’s like something you’d do if you had no access to any equipment. He’d use two cheap cassette recorders. If he wanted to hear drums, he’d record a human beat box rhythm for the length of the song—and most likely, he’d have the form of the song in his head while he was recording this. By the way, it was the same in the studio when he’d do his one man band approach to recording a song. He’d know the song in his head, and start out recording the drums for the song (it would essentially become the ‘click track’—the way a click track should be). Back to the cassette demo—he’d then play his beat box groove over the speaker on the cassette recorder and sing the bass line while recording all this onto the second cassette machine. He’d build up a rhythm track this way, and then add vocals. And there’s your demo.”
― Jake Brown, Prince "In the Studio" 1975 - 1995