I remember having a tape in the 90s, it was a copy of a copy of a copy of Large Professor's beats lol. Some of them I ended up hearing later on or they were already hits, but the majority were throwaways. You could tell they weren't finished but the tape sounded so shitty it was hilarious. But the beats were dope. It made me realize how much work goes into the mixing process.
I think one of the things about making beats today is with the tools we have it makes it easy to have a polished beat right away, which is great, but back then it was just about getting your ideas out and adding the polish later at the mixing stage. I'd love to hear stories from some of the engineers back then.