Not a lawyer, but that would be a fair use question, which I hear are notoriously complicated.
Colloquially, I generally expect a remix to be comprised of the original instrumentals/beat (potentially edited, but virtually nothing actually new added), potentially new lyrics, and to still be recognizable as the original.
The "still be recognizable as the original" part is a huge problem for fair use, and why I don't think remixes generally qualify. If it doesn't sound like the original then it's not a remix, but if it does sound like the original it can't be fair use.
I think the underlying issue is the resulting work, not the process that went into creating it. I think (but am in no way sure) that copying parts of songs would be fine if you did something to them so they aren't recognizable as the original.
As an example, if I take a song by the Beatles and repeatedly compress it until it's entirely compression artifacts, I would bet that I could publish that. I don't think it would matter that I started with a copyrighted work, what matters is that my finished product bears no resemblance to any other copyrighted work.
That would mean it's just a normal "is this work too similar to existing works?" standard applied to humans as well.
There is still an ancillary question of whether it's okay to train on copyrighted music, but that's really a different question than whether the works it creates infringe.
Colloquially, I generally expect a remix to be comprised of the original instrumentals/beat (potentially edited, but virtually nothing actually new added), potentially new lyrics, and to still be recognizable as the original.
The "still be recognizable as the original" part is a huge problem for fair use, and why I don't think remixes generally qualify. If it doesn't sound like the original then it's not a remix, but if it does sound like the original it can't be fair use.
I think the underlying issue is the resulting work, not the process that went into creating it. I think (but am in no way sure) that copying parts of songs would be fine if you did something to them so they aren't recognizable as the original.
As an example, if I take a song by the Beatles and repeatedly compress it until it's entirely compression artifacts, I would bet that I could publish that. I don't think it would matter that I started with a copyrighted work, what matters is that my finished product bears no resemblance to any other copyrighted work.
That would mean it's just a normal "is this work too similar to existing works?" standard applied to humans as well.
There is still an ancillary question of whether it's okay to train on copyrighted music, but that's really a different question than whether the works it creates infringe.