This is kind of a hoot.
On one level? It's easily possible to make a bunch of recordings of songs that never happened by artists who did. I never thought of it before, but I absolutely know how to do it. With a few months to set up, I could start putting out never-released Elvis Presley albums, with the actual voice on the tape (or CD) indistinguishable from genuine Elvis at whatever stage of his career this fake album was supposed to be from. Or albums the Doors never released, or whatever... This is totally possible, and would be a hoot! I could build an entire album collection of cross-dimensional music!
The kicker? Absolutely couldn't have done it in 1990. Not enough compute power in the world at that time.
Well. Not enough in OUR world.....